Multiple-virus-resistant melon

ABSTRACT

The invention relates to a melon plant, and parts thereof including seeds and fruit, that is resistant to Zucchini Yellow Mosaic Virus (ZYMV) and Watermelon Mosaic Virus (WMV). The melon plant may further comprise resistance to Cucumber Mosaic Virus (CMV) and/or further display a Brix measurement of ≥9.5° Bx, orange flesh color, and/or a fruit width to length ratio of ≥0.5. Methods for producing such a plant are also provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims benefit of U.S. Provisional Application No. 61/692,643, filed Aug. 23, 2012, herein incorporated by reference in its entirety.

INCORPORATION OF SEQUENCE LISTING

The Sequence Listing, which is a part of the present disclosure, includes a computer readable 12.5 KB file created on Aug. 20, 2013 entitled “SEMB006US_ST25.txt” comprising nucleotide and/or amino acid sequences of the present invention submitted via EFS-Web. The subject matter of the Sequence Listing is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The invention relates to the field of plant breeding. More specifically, it relates to methods for producing melons resistant to multiple viruses, and plants produced therefrom.

BACKGROUND OF THE INVENTION

Melon fruits are highly appreciated worldwide and are often eaten as a fresh product. Melons are members of the gourd family (Cucurbitaceae), a class of trailing annual vines that also includes squash, pumpkin and cucumber. They have large broad leaves, stems covered in light prickles and small yellow flowers. The fruit themselves are soft fleshed with a central cavity containing seeds, surrounded by a thick protective rind. Taxonomically, melons are broadly divided into two groups: watermelons (species Citrullus lanatus) and muskmelons (species Cucumis melo L.). C. melo includes a wide variety of cultivars producing fruits of different shape, external appearance and flesh color, including such melons as Canary, Cantaloupe (including Western Shipper, North American and Charentais types), Casaba, Hami, Honeydew, Navajo Yellow, Piel de Sapo, Santa Claus, Sugar melon, Ambrosia, Bailan, Galia, Ogen, Persian, and Sharlyn.

Certain viruses are capable of infecting melons and causing crop damage and loss in many varieties. Examples of viral pathogens that may impact melon cultivation include Cucumber Mosaic Virus (CMV), Watermelon Mosaic Virus (WMV), and Zucchini Yellow Mosaic Virus (ZYMV).

SUMMARY OF THE INVENTION

In a first aspect, the invention provides a melon plant comprising resistance to Zucchini Yellow Mosaic Virus (ZYMV) and Watermelon Mosaic Virus (WMV), wherein the plant further comprises at least one trait selected from the group consisting of: produces fruit with a width to length ratio of at least 0.5; produces fruit with orange flesh color, green flesh color, or white flesh color; demonstrates fruit Brix≥9.5° Bx; displays resistance to CMV; displays resistance to MNSV; displays resistance to PRSV; and displays resistance to Powdery Mildew.

In one embodiment, the invention provides such a melon plant, wherein the at least one trait is a width to length ratio of at least 0.5. In other embodiments, the melon plant comprises at least one trait selected from the group consisting of orange flesh color, green flesh color, and white flesh color. In another embodiment of the melon plant, the at least one trait is Brix≥9.5° Bx. In yet another embodiment the at least one trait is resistance to CMV. In still yet another embodiment, the at least one trait is resistance to Powdery Mildew. In other embodiments the at least one trait is resistance to MNSV, or resistance to PRSV.

The invention further provides a part of such a melon plant, wherein the plant part is selected from the group consisting of: a seed, a root, a leaf, a stem, pollen, an ovule, an anther, a pistil, and a cell. A tissue culture of regenerable cells of the melon plant is also provided by the invention. In a particular embodiment, the tissue culture may comprise cells or protoplasts from a plant part selected from the group consisting of embryo, meristem, cotyledon, pollen, leaf, anther, root, root tip, pistil, flower, and seed.

Another aspect of the invention provides such a melon plant, which is inbred. Alternatively, the melon plant may be a hybrid.

A further aspect of the invention provides a method of determining the genotype of a melon plant comprising resistance to Zucchini Yellow Mosaic Virus (ZYMV) and Watermelon Mosaic Virus (WMV), wherein the plant further comprises at least one trait selected from the group consisting of: produces fruit with a width to length ratio of at least 0.5; produces fruit with orange flesh color, green flesh color, or white flesh color; demonstrates fruit Brix≥9.5° Bx; displays resistance to CMV; displays resistance to MNSV; displays resistance to PRSV; and displays resistance to Powdery Mildew; wherein the method comprises: obtaining a sample of nucleic acids from said plant and detecting in said nucleic acids a plurality of polymorphisms.

Also provided by the invention is a method of identifying a melon plant that displays resistance to Zucchini Yellow Mosaic Virus (ZYMV) and Watermelon Mosaic Virus (WMV), the method comprising: detecting in a first melon plant at least one allele of a marker that is associated with WMV and ZYMV resistance, wherein the marker is genetically linked within 10 centiMorgans (cM) of marker NU0219106 or NU0219710 on melon chromosome 11. In one embodiment of such a method, the marker is localized within a chromosomal interval defined by and including the terminal markers NU0219106 and NU0219710 on melon chromosome 11. In another embodiment, the marker is localized within a chromosomal interval defined by and including the terminal markers NCMEL008383077 and NU0220333 on melon chromosome 11. In particular embodiments of the method, the marker is selected from the group consisting of: NU0219106, NU0218916, NU0219099, NU0218656, NCMEL008383076, NCMEL008383077, NU0218779, NCMEL008383075, NCMEL008383078, NU0220333, NU0219293, NU0218835, NU0244142, and NU0219710.

In some embodiments, the detecting comprises detecting at least one allelic form of a single nucleotide polymorphism by PCR, single strand conformational polymorphism analysis, denaturing gradient gel electrophoresis, cleavage fragment length polymorphism analysis, TaqMan assay, and/or DNA sequencing.

The invention further provides a method of identifying a melon plant that displays resistance to Zucchini Yellow Mosaic Virus (ZYMV), the method comprising: detecting in a first melon plant at least one allele of a marker which is associated with ZYMV resistance, wherein the marker is genetically linked within 2 centiMorgans (cM) of marker NU0218531 on melon chromosome 2. In certain embodiments, the marker is localized within a chromosomal interval defined by and including the terminal markers CMBR041 and NU0218531 on melon chromosome 2. In particular embodiments of the method, the marker is selected from the group consisting of CMBR041, and NU0218531.

The method may further comprise detecting at least one allele of a marker that is associated with CMV resistance, and at least one allele of a marker that is associated with WMV and ZYMV resistance. Thus, in such a method, at least one allele of a marker associated with resistance to CMV is detected in the melon plant within a chromosomal interval defined by and including the termini NU0243358 or NU0218323 on melon chromosome 12; or within a chromosomal interval defined by and including the termini NU0219184 and NU0218323 on melon chromosome 12; or within a chromosomal interval defined by and including the termini NU0220476 or NU0219006 on melon chromosome 2, or wherein the marker is genetically linked within 10 cM of markers NU0243358 or NU0219184 or NU0218323, or genetically linked within 10 cM of markers NU0220476 or NU0219006.

In certain embodiments of the methods, the resistance is assayed by exposing the plant to WMV or ZYMV, and identifying plants with reduced disease symptom expression relative to control plants.

In some embodiments of the methods, the at least one allele of a marker associated with resistance to WMV or ZYMV is found in melon line ME8094, a representative sample of seed of which has been deposited under NCIMB accession number 41653. The invention may further comprise selecting the first melon plant from a population of melon plants based on the presence of said allele of a marker which is associated with the resistance to ZYMV or WMV. In particular embodiments the method further comprises crossing a selected first melon plant with a second melon plant to obtain a progeny plant of a subsequent generation. Certain embodiments of the methods of the invention further comprise backcrossing the progeny plant of a subsequent generation and at least one further subsequent generation thereof to a recurrent parent until a backcrossed progeny plant is produced that comprises resistance to WMV or ZYMV.

Another aspect of the invention provides a method of producing a melon plant having resistance to WMV and ZYMV, comprising the steps of: (a) crossing a plant of melon line ME8094, or a progeny thereof comprising resistance to WMV and ZYMV, derived from said line ME8094, with a second melon plant having at least one desired trait, a representative sample of seed of said line having been deposited under NCIMB accession number 41653; and (b) selecting at least a first progeny melon plant resulting from the crossing that comprises resistance to WMV, and ZYMV, and at least one desired trait.

In some embodiments of such a method, the desired trait is selected from the group consisting of: a width to length ratio of at least 0.5; orange flesh color; Brix≥9.5° Bx; resistance to CMV; resistance to MNSV; resistance to PRSV; and resistance to Powdery Mildew. In other embodiments, selecting the first progeny comprises identifying the presence of at least a first genetic marker in the first progeny that is genetically linked to a locus contributing to resistance to WMV, ZYMV, or CMV; wherein the marker genetically linked to a locus contributing to WMV or ZYMV resistance maps to chromosome 11, and wherein a marker genetically linked to a locus contributing to CMV resistance maps to chromosome 2 and/or 12. In particular embodiments, selecting the first progeny further comprises selecting the progeny based on the presence of a plurality of genetic markers from the second melon plant present in the progeny. Thus, in some embodiments the invention provides a method wherein the genetic marker linked to a locus contributing to WMV or ZYMV resistance is genetically linked within 10 cM of marker NU0219106 or NU0219710 on melon linkage group 11. In further embodiments the genetic marker linked to a locus contributing to CMV resistance is genetically linked within 10 cM of marker NU0243358 or NU0218323 on melon linkage group 12 or within 10 cM of marker NU0220476 or NU0219006 on melon linkage group 2.

In certain embodiments the genetic marker is selected from the group consisting of: NU0219184, NU0219714, NU0220980, NU0243527, NU0220836, NU0218164, NU0218516, NU0218074, NU0218603, and NU0220144. In other embodiments the genetic marker linked to a locus contributing to CMV resistance is genetically linked within 10 cM of marker NU0220476 or NU0219006 on melon linkage group 2. In still other embodiments the genetic marker is selected from the group consisting of: NU0218624, NU0219047, NU0220488, and NU0220264. In particular embodiments the genetic marker linked to a locus contributing to WMV or ZYMV resistance is NU0218656 or NU0218779.

Further embodiments of such a method comprise the step of: (c) crossing the progeny plant with itself or a third plant to produce a progeny plant of a subsequent generation. Yet other embodiments further comprise the steps of: (d) crossing the progeny plant of a subsequent generation with itself or a second plant; and (e) repeating steps (c) and (d) for at least an additional 3-10 generations to produce an inbred melon plant derived from melon line ME8094, a representative sample of seed of said line having been deposited under NCIMB accession number 41653. In particular embodiments said progeny plant of a subsequent generation is selected for crossing based on the presence of resistance to WMV or ZYMV, and the desired trait. In certain embodiments the progeny plant of a subsequent generation is selected at each generation for crossing based on the presence of the resistance to WMV or ZYMV, and the desired trait. The method may further comprise selecting the progeny plant of a subsequent generation by identifying the presence of at least a first genetic marker in the first progeny that is genetically linked to a locus contributing to resistance to WMV and ZYMV. In some embodiments, selecting the progeny plant of a subsequent generation further comprises selecting the progeny based on the presence of a plurality of genetic markers from the second melon plant present in the progeny. In further embodiments step (e) is repeated a sufficient number of generations to obtain an inbred melon plant that comprises resistance to WMV, and ZYMV, and further comprises the agronomic traits of the second melon plant.

Yet another aspect of the invention relates to a melon plant, or a part thereof, produced by such a method. A part of such a melon plant, wherein the part is selected from the group consisting of: a fruit, a leaf, a root, a stem, pollen, an ovule, a cell, and a seed, is also provided, as is hybrid melon seed produced by such a method.

Thus, in certain embodiments, the invention provides a melon seed defined as produced by a method comprising: crossing variety ME8094, a representative sample of which has been deposited with the NCIMB, Aberdeen, Scotland under accession number NCIMB 41653, or a progeny thereof, with a second melon variety; detecting the genotype or virus resistance phenotype of a progeny plant of a subsequent generation; and harvesting seed thereof.

An inbred melon seed of line ME8094, a representative sample of which has been deposited with the NCIMB under accession number NCIMB 41653, is a further aspect of the invention, as is a plant grown from the seed of ME8094, and a part of the plant. In some embodiments the plant part is selected from the group consisting of: a fruit, a leaf, a root, a stem, pollen, an ovule, a cell, and a seed.

Yet another aspect of the invention provides a melon plant, or a part thereof, having all the physiological and morphological characteristics of a plant of melon line ME8094. A tissue culture of regenerable cells of the plant is also provided. In further embodiments, the plant of melon line ME8094 further comprises a single locus conversion. In other embodiments the plant comprises a transgene.

Another aspect of the invention provides a method of producing melon seed, comprising crossing the plant of melon line ME8094 with itself or a second melon plant. Thus, the invention also provides an F1 hybrid seed produced by such a method, as well as an F1 hybrid plant produced by growing such a seed.

In still another aspect, the invention provides a method of vegetatively propagating a melon plant comprising the steps of: (a) collecting tissue capable of being propagated from a plant of melon line ME8094; (b) cultivating said tissue to obtain proliferated shoots; and (c) rooting said proliferated shoots to obtain rooted plantlets. Certain embodiments of this method further comprise growing plants from said rooted plantlets.

BRIEF DESCRIPTIONS OF THE FIGURES

FIG. 1 diagrams the melon genetic map, showing relative positions of selected traits of interest on linkage groups (Chromosomes) 1-12.

FIG. 2 illustrates the level of viral disease symptoms conferred by resistance traits present in melon line ME8094 when challenged with CMV, WMV, or ZYMV, as compared with other selected melon lines. “Y” axis is denoted by symptom rating scale (1-10).

FIG. 3 illustrates the viral titer detected by ELISA in melon line ME8094, after challenge with CMV, ZYMV, or WMV, as compared with other selected melon lines.

FIG. 4 provides a table showing relative disease scores (1-10 scale) and ELISA scores of selected melon lines when challenged with listed pathogen(s) (i.e. viral isolate).

FIGS. 5A-5C provide disease rating scores and AUDPC for plants of melon varieties inoculated with indicated CMV strain, scored at 8, 15, and 30 days after infection. (MDI-8, -15, -30). Entry # and Variety columns in 5A apply as corresponding labels also for the FIG. 5B and FIG. 5C data columns.

FIGS. 6A-6E provide photographs of fruit from ME8094 and BC2 lines derived therefrom. FIG. 6A: fruit of ME8094; FIG. 6B: fruit of C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0027.0018.0006; FIG. 6C: fruit of C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0080.0088.0005; FIG. 6D: fruit of C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0063.0007.0010.0147; FIG. 6E: fruit of C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0018.0013.0002.0145.

FIG. 7 illustrates additional trial results for traits of each of the two tested GAL BC3 families carrying the ZYMV/WMV QTL11 introgression (homozygous donor (DN) and recurrent parent (RP) alleles next to the unconverted inbred lines (FS)) respectively.

FIG. 8 illustrates data of Table 11 (trial of the AMA-188-DECO-AN MABC conversion carrying the ZYMV/WMV QTL11 introgression), in graphic form. Results from homozygous donor (DN) and recurrent parent (RP) alleles are next to the unconverted inbred lines (FS). One BC4 family was evaluated for listed phenotypic traits. Least square means and least square differences are shown.

FIG. 9. Genotypes at ZYMV/WMV QTL11 of the trialed isogenic lines: donor introgressions span 2.2 to 9.1 cM. Dark highlighted or underlined markers demonstrate the most likely interval where the trait resides.

FIG. 10. Representation of fingerprinting data and allele information from two events carrying the ME8094 introgression at the ZYMV/WMV QTL11 locus that lacked linkage drag (deleterious phenotype) and were shown to be resistant to ZYMV and WMV.

FIG. 11. Photographs showing typical size/shape and blossom end scar of melons carrying introgressions at the CMV QTL12 genomic region.

FIGS. 12A-B. Genotypes and phenotypes (lsmeans of AUDPC and 14 dpi score for each of the two timepoints described above) of available entries with recombination events in the CMV QTL12 interval and controls. In FIG. 12B, darker highlighting corresponds to ME8094 introgressions at given marker locations, and lighter highlighting to introgressions of the recurrent parent WSH-39-1083-AN. Putative location of the genetic factor controlling CMV is in the interval of NU0243358 and NU0218323.

FIG. 13. Genotypes at the CMV QTL12 of the isogenic lines trialed. The fine-mapped region of the QTL is shown within the bold lines and markers at positions 43.38 and 44.47 cM are the most closely linked to the trait.

FIG. 14. Three events carrying the ME8094 introgression at the CMV QTL12 locus that lacked linkage drag were shown to be intermediate resistant (IR), resistant (R) and highly resistant (HR) under CMV pressure.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides methods and compositions for producing multiple virus resistant melon plants exhibiting resistance to Watermelon Mosaic Virus (WMV) and Zucchini Yellow Mosaic Virus (ZYMV), and Cucumber Mosaic Virus (CMV), while also exhibiting one or more agronomically acceptable traits such as high Brix content, desirable fruit flesh color (e.g. orange, green, or white), desirable fruit shape (length-width ratio), non-pentamerous fruit, and lack of andromonoecious flowers, among others. Methods of breeding and selecting multiple virus resistant melon lines are further provided, as well as plants, seeds, and fruit of such multiple virus resistant melons. Also disclosed herein are molecular markers that are linked to quantitative trait loci (“QTL”) contributing to such plant virus resistance.

Surprisingly, the inventors have been able to develop methods and compositions that allow, for the first time, production of plants with multi-virus resistance while avoiding or minimizing deleterious traits that have thus far been associated with such viral resistance. Examples of deleterious traits that have been associated with attempts to obtain resistance to individual viruses include weak plants with pentamerous, flat, poorly netted fruit, poor net formation, low fruit set, foliar necrosis, and andromonoecy. In contrast, the invention provides methods and compositions that permit combination of multi-virus resistance with the ability to produce a commercially acceptable melon crop from a single line.

The ability to produce virus resistant plants is also hampered by difficulties in phenotyping and the limited repeatability of phenotyping for virus resistance. This includes problems associated with limited heritability of some resistance phenotypes. For instance, with regard to CMV, inconsistent disease reactions may occur in sequential tests on selected breeding lines.

The invention represents a significant advance in the art in that it provides, in certain embodiments, methods and compositions permitting introgression or resistance to selected viruses and combinations of viruses into a commercially acceptable genetic background. In specific embodiments of the invention, a QTL conferring WMV and ZYMV resistance is identified and defined by the map interval bounded by markers NU0218779 and NU0218835 (see Table 4), corresponding to 44.6-49 cM on melon chromosome 11. A QTL is also identified herein that confers resistance to CMV and is located on chromosome 12 in the interval bounded by markers NU0243358 and NU0218323, spanning the interval of 39.7-44.47 cM. Additionally, a second QTL that confers resistance to CMV is identified herein that is located on chromosome 2 in the interval bounded by markers NU0220476 and NU0219006, spanning the interval of 80.1-118.5 cM.

Further, the zym-1 gene specifying resistance to ZYMV was also mapped, and markers CMBR041 (Diaz et al., BMC Plant Biol. 11:111, 2011), NU0218808, NU0218497, NU0218113, NU0244013, NU0244734, NU0220855, NU0244741, NU0220997, NU0220034, NU0220178, NU0218179, NU0243740, and NU0218531, corresponding to the interval from ˜3.2-5.7 cM on the genetic map of melon chromosome 2 were found to be tightly linked to this gene.

Through use of the corresponding markers provided herein and/or other markers that may be linked thereto, one of skill in the art may use genetic markers to introgress and combine (“stack”) virus resistance traits in commercially relevant hybrid varieties and melon lines.

In accordance with the invention, identified QTL may be introgressed into any different melon genetic background. Thus, using the methods of the invention and starting from the genetic sources identified herein or available in the art, a melon plant of any genotype may be produced that further comprises the desired viral resistance, including WMV, ZYMV, and CMV. In addition, such plants may be prepared to comprise other desired traits, for example elite agronomic and fruit quality traits as desired.

Sources of particular resistances are known in the art, although the ability to combine such sources in a commercially relevant way as described herein has been lacking. An example is melon lines derived from the source PI 414723 having resistance to one or more of ZYMV, CMV, or WMV, such as ‘Hannah's Choice F1’ (Henning et al., 2005, Hort. Sci 40: 492-493). While the source provides viral resistance, the heritability of the viral resistance is often complex, the genetic position of resistance unknown, the resistance trait is associated with deleterious traits, and there are problems with pathogen specificity. For instance, ZYMV occurs in three pathotypes designated as 0, 1 and 2. The ZYMV resistance trait from accession PI 414723, specified by the zym-1 gene, confers resistance to pathotype 0 but does not provide any resistance against pathotype 2. Furthermore, infection with pathotype 1 may result in large scale necrosis in plants carrying the ZYMV resistance trait from accession PI 414723. The herein described WMV/ZYMV resistance locus provided on chromosome 11 is valuable as it provides resistance to two viruses, strong resistance to WMV, no or very low virus titer after mechanical viral inoculation, and a source for resistance to ZYMV which is not associated with the foliar necrosis typical of the previously identified zym-1 gene.

With respect to its underlying genetics, ZYMV resistance from accession PI 414723 is polygenic (Danin-Poleg et al., Euphytica 93:331-337, 1997), meaning that multiple loci are required to confer resistance. This hampers breeding efforts as only a portion of progeny plants in a breeding program will carry all or even some of the genes necessary to confer an adequate level of resistance. Additionally, ZYMV resistance in accession PI 414723 is linked to andromonoecy (plants having both hermaphrodite and male flowers). Since elite melon breeding lines are desirably monoecious lines (plants having separate male and female flowers) and monoecious parental lines do not require tedious and expensive hand emasculation to avoid self-pollination, andromonoecy is considered to be an undesirable characteristic. Also, fruit of monoecious F1 hybrids lack the undesirable blossom end, thus producing fruits of higher quality.

Another problem associated with virus resistance originating from PI 414723 is the lack of further characterization of these resistance traits regarding WMV. In contrast to the observation in Henning et al. (supra) that PI 414723-4, a resistance-selected line of PI 414723, is resistant to WMV, other researchers could not confirm the presence of WMV resistance in PI 414723 (e.g. Díaz et al. 2003, Plant Dis. 87:960-964). In addition, the WMV resistance trait from accession PI 414723 did not confer resistance to some isolates of WMV (Anagnostou et al., 2003, J. Euphytica 116:265-270), and therefore cannot serve as source for broad WMV resistance.

WMV resistance has been described, such as the recessive trait in C. melo accession TGR-1551 (Díaz-Pendón et al. 2005 Phytopathology 95:840-846; and Díaz et al. supra). Like the WMV resistance originating from PI 414723, the WMV resistance from TGR-1551 does not confer resistance to some isolates of WMV (see FIG. 4). Hence, C. melo accession TGR-1551 is less desirable as a donor of the trait “WMV resistance” in breeding programs. Incorporating a previously known source for CMV resistance may be problematic in breeding for such resistance as well, in that it is linked to an undesirable trait that results in pentamerous fruit, as further discussed below. Thus the newly disclosed QTL for CMV resistance is also of great benefit for melon breeding.

Genetic Mapping of Loci Controlling Virus Resistance

Viruses of interest, sources (donors) for resistance, and mapping populations used to identify loci controlling virus resistance are listed in Table 1. A summary of genetic parameters relating to identified virus resistance traits is found in Table 2. Genetic parameters listed in Table 2 include the linkage group and projected location on the chromosome of the resistance loci; the additive (Add. Effect) and dominance (Dom. Effect) effects of the favorable allele at each locus; the percent of phenotypic variance (“Model R{circumflex over ( )}2”) accounted for by genotype at each locus; and the mean phenotypes of families in the mapping populations with genotypes homozygous for the unfavorable allele (Pheno. Homoz. Unfav), heterozygous (Pheno. Het), and homozygous for the favorable allele (Pheno. Homoz. Fav). The phenotypic rating scales used for each virus are 1 to 3=resistant; 4 to 6=intermediate resistant; 7 to 9=susceptible. The specific phenotypes associated with each numerical score differ per virus based on specific manifestations of the diseases, but the three general categories of resistant; intermediate resistant; susceptible are consistent.

TABLE 1 Virus resistance traits, sources, and allele information used to identify loci controlling resistance to viruses in melon. (“Generation” refers to the progeny generation of a given mapping population. Source of Gene/ Unfavorable Favorable QTL Allele Favorable Trait Allele ID Parent Allele Parent Generation CMV Mbnr992 QTL12 GA35Pmt Mbnr992 F6 CMV PI161375 QTL12 Vedrantais PI161375 F6 WMV Mbnr992 W/z GA35Pmt Mbnr992 F6 ZYMV Mbnr992 W/z GA35Pmt Mbnr992 F6 ZYMV PI414723 zym-1 Vedrantais PI414723 F6

CMV, WMV and ZYMV resistance was mapped from source Mbnr992 (Table 1), which was developed by self-pollination of ME8094. Mbnr992 carries resistances to CMV, WMV, and ZYMV. Inheritance of the CMV and ZYMV resistances from Mbnr992 is recessive. Inheritance of WMV resistance from Mbnr992 is mainly dominant, although heterozygotes may show intermediate resistance depending on weather conditions and the level of virus pressure. When using Mbnr992 as the resistance donor for breeding, segregating populations demonstrated high correlation of resistance to both WMV and ZYMV. This suggested tight linkage of loci (or a single locus) controlling resistance to these two viruses, which was confirmed by additional mapping studies.

CMV resistance was mapped from two sources, Mbnr992 and PI161375 (see Table 1). Mbnr992 is discussed above. An F6 RIL population from the cross Mbnr992 x GA35Pmt was phenotyped and genotyped to map the genetic location of the resistance trait. The parent line GA35Pmt is susceptible to CMV, WMV, and ZYMV. PI161375 is resistant to CMV and MNSV (MNSV resistance is conferred by the nsv locus). An F6 RIL population from the cross PI161375 x Vedrantais was phenotyped and genotyped. The parent line Vedrantais is a Charentais type, inbred line susceptible to CMV and MNSV.

QTL for CMV resistance in Mbnr992 x GA35Pmt and in PI161375 x Vedrantais populations were identified. Both populations carry a QTL on chromosome 12. An allelism test including >1000 F2 plants from Mbnr992 x Virgos (a CMV-resistant derivative of PI161375 x Vedrantais) supported allelism of the major effect(s) for CMV resistance from the two sources (Mbnr992 and PI161375). The mapping and allelism test support a common QTL on chromosome 12. A second CMV resistance QTL was also identified on chromosome 2 in the Mbnr992 cross (Table 2).

TABLE 2 Genetic parameters of selected loci controlling resistance to viruses in melon. Source of Projected Pheno. Pheno. Favorable Gene/ Linkage position Add. Dom. Model Homoz. Pheno. Homoz. Trait Allele QTL ID Group on Chrom. Effect Effect R{circumflex over ( )}2 Unfav. Het. Fav. CMV Mbnr992 QTL12 12 35-47 −2.00 −0.09 0.52 6.1 2.1 CMV Mbnr992 QTL02 2  97-107 −0.74 −0.74 0.10 4.6 3.1 3.1 CMV PI161375 QTL12 12 35-47 −1.50 NA 0.41 7.8 NA 4.6 WMV Mbnr992 W/z 11 44-53 0.00 Complete na Sus. Res. Res. ZYMV Mbnr992 W/z 11 44-53 0.00 0.00 na Sus. Sus. Res. ZYMV PI414723 zym-1 2 3.2-5.7 0.00 0.00 na Sus. Sus. Res.

Table 3 shows exemplary contemplated breeding strategies with certain representative embodiments for production of F1 hybrid elite melon plants comprising agronomic traits of interest, including multiple (stacked) virus resistance. “PM” denotes a source for resistance to Powdery Mildew of melon. Likewise, WMV, ZYMV, and CMV denote the corresponding virus resistance traits. For instance, “CMV12” indicates the presence in a parent plant of a genetic trait conferring CMV resistance, and which is localized on melon Linkage Group 12. Other desirable agronomic traits such as additional disease resistance(s), orange or green fruit flesh color, rounded fruit, and enhanced Brix, among others, may also be contemplated for inclusion in the resulting F1 hybrid plants. A skilled worker may adjust the breeding strategy as needed, for instance in view of disease resistance and other traits desired for a given market or melon growing geographic region.

TABLE 3 Exemplary breeding strategy for traits that may be combined to produce an F1 hybrid multiple virus resistant melon. Female parent Male parent PM WMV/ CMV12 CMV02 PM WMV/ CMV12 ZYMV ZYMV PM WMV/ CMV12 PM or WMV/ CMV12 ZYMV increased ZYMV Brix

Improved Melon Lines with Multi-Virus Resistance

Resistance to particular pathogens such as CMV, WMV, and ZYMV have been described. For ZYMV and WMV, resistant accession PI 414723 was reported by Pitrat and Lecoq (1984, Euphytica 33: 57) and Anagnostou et al., 2003 (J. Euphytica 116: 265-270). The resistance is heritable but associated with andromonoecy, which is undesirable in melon lines used for breeding (Pitrat et al., Phytopathol. 70:958-961, 1980). Additionally, PI 414723 displayed a necrotic phenotype upon infection with ZYMV pathotype 1. Necrosis is often associated with disease resistance; thus, heavy infection with pathotype 1 could lead to reduction of plant development and yield loss.

In contrast to the previous problems, ZYMV resistance is provided by the present invention not linked to the andromonoecious characteristic. This finding thus facilitates the production of a homozygous ZYMV resistant, monoecious line that can be used as donor in breeding programmes for introgression of these traits into new cultivars.

In contrast to PI414723, the melon line ME8094 described herein was found to be fully resistant to ZYMV pathotype 1 and not display necrosis. ME8094 did not display symptoms upon infection, nor contain ZYMV virus titer, as evidenced by ELISA.

Additionally, ZYMV resistance was found to be closely linked to WMV resistance in ME8094. An F2 population was developed from ME8094 crossed with a susceptible inbred line. The population consisted of 255 individuals that were propagated in the absence of selection. Phenotypes of ZYMV and WMV resistance in F3 progeny derived from this population were determined. A subset of 56 F3 families was fully resistant to ZYMV, consistent with a single, recessive locus. This is a significant advance in that melon has 12 chromosomes and if resistance traits reside on different chromosomes many descendants of a cross will not inherit the resistance alleles. The invention thus provides, in one embodiment, plants with ZYMV resistance closely linked to WMV resistance. This renders it easier to fix such traits by selfing, backcrossing and selection. It is also easier to stack traits in this way. Hence, plants provided by the invention comprising such resistance, including ME8094 and any progeny thereof, can be used as a universal donor line for resistance to ZYMV, WMV, and/or CMV. Advantageously, a plant of the present invention may be characterized by the fact that the ZYMV and WMV traits are linked so closely that the genetic distance between the two loci is less than 6 cM, 5 cM, 4 cM, 3 cM, 2 cM, 1 cM, 0.1 cM, or 0.01 cM, or the genetic distance is essentially equal to 0 cM.

Unexpectedly, the WMV resistance produced according to the invention provided other advantages in addition to linkage to ZYMV resistance. Resistance to WMV from accession PI 414723 (Anagnostou et al., 2003, J. Euphytica 116:265-270) did not confer resistance to some isolates of WMV, and therefore cannot serve as a broad source of resistance for this resistance trait. Similarly, it appears from the work by Diaz-Pendon et al. (2005, Phytopathol. 95:840-846) that TGR1551 still may carry virus particles, even if it does not show pathological effects relating to WMV, and in work reported here does not appear to display broad spectrum resistance. In contrast to plants comprising such virus resistance traits from PI414723 and TGR1551, it was found that melon plants could be produced such as ME8094 that gave broader spectrum resistance and did not display symptoms upon infection, nor contain WMV virus-titer as evidenced by ELISA. Furthermore, heritability of virus resistances for ZYMV, WMV and CMV from Line ME8094 was shown to be advantageously high. The trait can thus be introgressed in a desired genetic background as described herein. Successful introgression of, for instance, the ZYMV and WMV virus resistance markers from ME8094, accompanied by desirable agronomic traits including fruit length and width, cavity size, firmness, Brix, and rind and flesh color, is described in Example 4 and FIG. 6.

Thus, the viral resistance provided herein represents a significant advance over the art. For instance, resistance to ZYMV is not linked to the unfavourable andromonoecy trait. Also, resistance was demonstrated against all known isolates of ZYMV. Additionally, ZYMV resistance is linked to WMV resistance. This results in increased speed and cost reduction in the development of plants carrying both resistance specificities. Fourth, resistance was conferred, and the presence of the virus was not detectable.

The present inventors now have provided melon plants wherein the sources for resistances to ZYMV and WMV, as well as CMV, have been successfully combined. An example is the inbred line ME8094, which has been demonstrated to have high resistance to CMV (shown by DAS-ELISA by the α-CMV isolate V6; e.g. see FIGS. 3-4), resulting in a mean disease index which is even lower than the index of the ‘resistant’ line TIGR 1551. With respect to the resistance to ZYMV it has been shown that ME8094 is not affected by infection with ZYMV pathotype 1 (e.g. see FIGS. 2-4), in contrast to all other varieties tested. In a field test with virus field populations of ZYMV, WMV and CMV, no susceptible plants were found in accession ME8094. No other variety is known to harbor a resistance to all these viruses.

The identified resistance displayed a distinct mode of inheritance for each resistance specificity. The resistance to ZYMV was localized on one recessive locus and the resistance to WMV localized on one dominant locus. The resistance to CMV was localized on two additive loci. Additional disease resistance traits may be bred into plant comprising such resistance, including progeny lines of ME8094, particularly given the high heritability of the virus resistance. This includes resistance to CYSDV (Cucurbit Yellow Stunting Disorder Virus; e.g. EP 1800535; EP 1962578), CVYV(Cucurbit Vein Yellowing Virus; e.g. WO 2010/025747), PRSV(Papaya Ring Spot Virus; e.g. Brotman et al., TAG 110:337-345, 2005), MNSV (Melon Necrotic Spot Virus; e.g. WO 2003/066900), and/or Powdery Mildew, among others

A QTL analysis with respect to the viral resistance loci found that the resistance to WMV and to ZYMV co-located on the same linkage group, while the resistance to CMV was spread over 2 loci in different linkage groups. Hence, the traits could be localized to several specific quantitative trait loci (QTL). Further, it was established that ZYMV resistance is not linked to andromonoecy, which enabled the possibility of obtaining monoecious resistant plants, while the CMV QTL12 resistance trait was not closely linked to the undesirable pentamerous fruit trait.

These experimental data demonstrate that traits of resistance to ZYMV and WMV, and CMV, may be transferred to other melon varieties using melon accession ME8094 as a donor of a specific genetic region or regions, independent of andromonoecy. Thus, in certain embodiments, the present invention provides a melon plant of line ME8094 and seed thereof, and progeny of ME8094 and seed thereof, comprising such ZYMV and WMV resistance as is found in ME8094, as well as associated markers and methods for such marker-assisted breeding.

The skilled person will understand that individually inherited traits are observed in the entire population only after producing a segregating population (e.g. F2), and that fixing traits typically requires backcrossing and selfing.

Based on the above findings, the present inventors were able to develop melon plants comprising the above resistance loci, wherein said loci are not in their natural genetic background.

Producing Multiple-Resistant Melon Varieties

The present inventors have identified certain plant disease resistance traits located, for instance as follows:

-   -   1. a locus for CMV resistance on linkage group 12.     -   2. a locus for CMV resistance on linkage group 2.     -   3. a locus for WMV resistance on linkage group 11.     -   4. a locus for ZYMV resistance on linkage group 11.     -   In one embodiment of a method for producing a         multiple-virus-resistant melon variety, one may provide a first         inbred melon line with the alleles for CMV (and optionally PM),         and a second inbred melon line with the alleles for WMV and         ZYMV. Crossing of the two lines results in a hybrid and         expression of the recessive alleles can be achieved by selfing,         which also results in a successful fixation of the combination         of resistance traits. Additional disease resistance traits, for         instance conferring resistance to one or more other viruses,         such as CYSDV, may also be bred into a ZYMV, WMV, and CMV         resistant line.

In additional embodiments, desirable agronomic traits relating to fruit flesh color, Brix level, and length to width ratio, among others, may also be incorporated in progeny lines derived from a plant provided herein and/or by the methods herein described.

Definitive chromosome numbers have not yet been assigned to the melon chromosomes on which several of the resistance-conferring loci are located. However, the chromosomes may be designated by reference to the linkage groups (e.g. LG 12, 2, and 11) on which these and other genomic regions are located. The term linkage group is used herein to refer to a calculated genomic unit based on recombinational genetic mapping, on which the resistance alleles are located, and which has the same hierarchical level as a chromosome. Some traits that have been studied in the public domain were found to be contained in these linkage groups. LG 12, harboring the major locus for CMV resistance, was found to be linked to the traits PM, and pentamerous. Finally LG 11, harboring the loci for both WMV and ZYMV resistance, was found to be linked to the trait Fom-2, but not to andromonoecious. The Fom-2 trait can be used as a marker and thus may also be used to assist in the selection of plants comprising the introgression of interest.

In addition to plants, the invention further provides seeds of the plants of the invention. These seeds are characterized in that they develop into plants of the invention. Said seeds can be obtained after selfing, crossing, or backcrossing the plant of the invention. The invention further provides plants, or plant parts, originating from said seeds. The invention further provides fruit, or fruit parts, originating from the plant originating from said seeds.

The invention further provides a method to transfer the genetic loci associated with resistance to novel melons without conferring deleterious traits such as andromonoecy.

The present invention further provides a method of producing plants of a melon line resistant to ZYMV, WMV, and/or CMV. In one embodiment, the method comprises the steps of;

-   -   a) crossing a plant of a recipient melon breeding line not         harboring the desired resistance with a plant of a donor melon         breeding line harboring the desired resistance;     -   b) collecting the seeds resulting from the cross in step (a),     -   c) regenerating the seeds into plants;     -   d) providing one or more backcross generations by crossing the         plants of step (c) or (optionally selfed) offspring thereof with         one or more plants of said recipient melon breeding line to         provide backcross plants;     -   e) selfing plants of step (d) and growing the selfed seed into         plants;     -   f) optionally repeating said steps of backcrossing and selfing         of steps (d) and/or (e);     -   (g) identifying and selecting from the plants grown in step (e)         or (f) plants that show the desired resistance.         In one embodiment, the identification and selection of plants in         step (g) is performed according to the methods listed below.

Determination of Resistance

Resistant plants can be detected by screening for the presence of virus in plant material. Viruses can be detected by ELISA, using standard methods with commercially available antibodies for the various viruses and molds, such as obtainable from Plant Research International (PRI, Wageningen, the Netherlands), Agdia Inc. (Elkhart, Ind., USA), Neogen Europe Ltd. (Auchincruive, Ayr, Scotland), Monogram Biosciences Inc. (f.k.a. ViroLogic Inc., South San Francisco, Calif., USA). Usually a double antibody sandwich ELISA (DAS-ELISA) protocol is suitable. Alternatively bioassays can be performed for the various diseases.

CMV resistance or susceptibility for instance may be detected by germinating melon seeds and growing the seedlings under standard conditions in a greenhouse on a test table. Susceptible controls may for instance include Vedrantais and PMR5, whereas as resistant controls Freemans cucumber, ME8094, and Virgos may be used. Mock-inoculated plants may be generally included. A day temperature of 20° C. and a night temperature of 18° C. is typically maintained. During periods with low light intensity, seedlings may be grown under artificial light for 16:8 hours day and night, respectively. Maintenance of the correct temperature is important to the success of the assay. Especially high temperatures should be avoided, and during inoculation and during the assay the temperature is generally maintained below 20° C. As an inoculum, susceptible Vedrantais or PMR5 plants with severe mosaic on leaves can be used. Preparation of the inoculum is generally performed on ice in order to maintain virus virulence. Infected leaves are suitably crushed in tap water or in a suitable buffer using a (generally cooled) mortar and pestle and ½ tea spoon carborundum powder per 10 ml of plant suspension. The plants are suitably inoculated 2 or 3 days after transplanting of the seedlings when the first true leaf is observed with full extension of the cotyledons. Between 8 and 10 days after the first inoculation a reinoculation can be performed. The inoculation may entail the rubbing of the inoculation mixture on both cotyledons/first leaf of the plant using a piece of sponge or with the thumb and index finger. Results may be scored 8 days post inoculation (DPI) when plants show adequate symptoms, optionally 12 DPI if desired, and finally 14 DPI. First symptoms of CMV susceptibility are lesions which can be seen on the cotyledons. Furthermore between 6 to 10 days DPI top leaves show clear mosaic and/or chlorosis and plant growth of infected plants will be reduced. It may be desired that at least 90% of the susceptible control plants should be infected for susceptible scores. It may be beneficial that at least 90% of the resistant control plants show no symptoms. Multiple plants can be scored individually, during multiple repeats in multiple environments (geographic regions) to determine the phenotype of given line.

WMV can be detected by germinating melon seeds and growing the seedlings under standard conditions in a greenhouse on a test table. Susceptible controls may for instance include Vedrantais and PMR5, whereas as resistant controls TGR 1551, ME8094 and PI124112 may be used. Seedlings are generally grown at 22° C./20° C. day/night. Assay conditions include a temperature of 25° C. day and night. During periods with low light intensity, seedlings are generally under artificial light 16:8 hours day and night, respectively. Susceptible plants with severe mosaic on leaves can be used for inoculation. Preparation of the inoculum is generally performed on ice in order to maintain virus virulence. Infected leaves are suitably crushed in tap water or in a suitable buffer using a (generally cooled) mortar and pestle and ½ tea spoon carborundum powder per 10 ml of plant suspension. The plants are suitably inoculated 2 or 3 days after transplanting of the seedlings when the first true leaf is observed with full extension of the cotyledons. Between 8 and 10 days after the first inoculation a reinoculation can be performed. The inoculation may entail the rubbing of the inoculation mixture on both cotyledons/first leaf of the plant using a piece of sponge or with the thumb and index finger. Results may be scored 7 to 10 DPI when plants show adequate symptoms. A second observation may be performed 3 days after first monitoring and a third observation 14 DPI. Symptoms include a severe green mosaic on the leaves.

ZYMV for instance may be detected by germinating melon seeds and growing the seedlings under standard conditions in a greenhouse on a test table. Susceptible controls may for instance include Vedrantais and PMR5, whereas PI414723, ME8094, and PI175109 may be used as resistant controls. Seedlings are generally grown at 22° C./20° C. day/night. Assay conditions include a temperature of 25° C. day and night. During periods with low light intensity, seedlings are generally under artificial light 16:8 hours day and night, respectively. Susceptible plants with severe mosaic on leaves can be used for inoculation. Infected leaves are crushed in tap water or with the standard buffer using a cooled mortar and pestle. The plants may be dusted with a layer of carborundum or ½ tea spoon of carborundum powder may be added to every 10 ml of inoculum suspension. Preparation of inoculum generally takes place on ice in order to maintain virus virulence. Plant stage of first inoculation is suitably 2 or 3 days after transplanting of the seedlings when first true leaf can be seen and cotyledons have fully grown. Plant stage of reinoculation is suitably after 7 to 10 days and the 1st true leaf can be inoculated. Thereto, the inoculation mixture may be rubbed on both cotyledons/first leaf of the plant using a sponge. First observation is 7 DPI when plants show adequate symptoms; second observation is 12 DPI, if desired. The third observation is 14 DPI. First symptoms of ZYMV between 6 to 10 days DPI on top leaves show clear yellow mosaic, dark green mottling or even necrosis of the leaf and the plant growth of infected plants will be reduced. At least 90% of the susceptible control plants should be infected. At least 90% of the resistant control plants should not show symptoms.

Production of Resistant Melon Plants

A first step in the production of virus resistant melons often comprises crossing a plant of a melon line in which the virus resistance trait is present in the parent 1 (P₁) or an offspring plant thereof having all disease resistance characteristics, and using a plant of a melon breeding line to which the resistance traits are to be introgressed as parent 2 (P₂). Generally an inbred line P₁ is the donor parent, and P₂ is the recipient parent. Said crossing will result in an F₁ progeny or offspring population containing two sets of homologous chromosomes obtained from both parents. This first step will result in a hybrid F₁ population.

It is not necessary to perform a genotypic or phenotypic analysis of the progeny of this first cross in which inbreds are crossed, as all plants of the F₁ population have the same genotype. The resulting plant population (representing the F₁ hybrids) may be selfed to produce F₂ seeds, but may be backcrossed to produce a BC₁ population using a plant of line parent P₂ as the recurrent parent. The BC₁ seeds or F₂ seeds or the plants grown therefrom may then be screened for having the resistance trait by performing resistance bioassays as described herein. In such a segregating BC₁ or F₂, this phenotypic analysis can assist in selecting those plants that are most suited for use in further breeding. In order to avoid the necessity to await the results of a phenotypic analysis of the BC₁ or F₂, the presence of a QTL associated with the resistance of interest can suitably be established and screened using a marker linked thereto in order to follow the trait by marker assisted breeding (MAB) or marker assisted selection (MAS) methods. Such a genotypic screening for the presence of the resistance trait may greatly speed up the breeding process. If desired, the BC₁ or F₂ seeds or further progeny seed obtained by the methods of the invention, or the plants grown therefrom may be screened for the presence of the trait by both genotypic and phenotypic methods as described herein.

The transfer of the genetic loci for resistance can be brought about by crossing. During plant crossing, various introgressions will generally be observed. Alternatively, the transfer may be brought about by genetic engineering. Both methods result in a recombinant plant, wherein DNA that is originally present at a specific location within the chromosome is exchanged for DNA from another plant (i.e. maternal for paternal or vice versa).

To obtain the genetic loci in a desired background, the segment on the specific linkage group(s) associated with the resistance may be introgressed into the genome of a plant of a melon breeding line, by one or more steps of crossing and backcrossing as described above and selecting from the progeny those plants that exhibit agronomically desirable characteristics, such as, but not limited to, insect resistance, valuable fruit characteristics including Brix level, flesh color, fruit shape, yield, etc., in combination with the traits of ZYMV, WMV, and CMV resistance, and for instance optionally PM resistance. This will result in a situation wherein the resistance allele is no longer in its natural genetic background, but is introgressed in the genetic background of the melon line of interest.

In another aspect of the invention an elite line is produced by consecutive steps of backcrossing to the recurrent parent in order to make the line an increasingly pure elite and inbred (inbred line). Alternatively, or in combination, the double haploid technique is applied. Thus, the present invention also provides methods for producing elite lines having resistance to ZYMV, WMV, and/or CMV. The elite lines may be produced by the methods of the invention to comprise one or more introgression(s) conferring the desired virus resistance. One example of an introgression involves introgression of a QTL found in melon accession ME8094.

Optionally, the above described melon plants can be selfed to provide inbred lines essentially homozygous for the alleles conferring resistance. Alternatively, or in combination, the double haploid technique is applied.

The optionally inbred or double haploid, melon plants obtained by the above described methods of backcrossing and optional selfing and/or DH production, can further be used to produce hybrids, by crossing with plants of other, optionally inbred, melon lines or other elite melon lines. The invention thus further provides a method of producing hybrids by crossing a melon plant obtained by a method of the invention with a plant of a melon inbred or elite line. These hybrids can be homozygous or heterozygous for the alleles conferring ZYMV, WMV, and/or CMV resistance. The hybrid may be homozygous for the alleles conferring ZYMV, WMV, and/or CMV resistance as expression of the phenotype is then optimal. However, in the case of dominant resistance traits, homozygosity for the allele is not required.

The invention further pertains to the plants, or part of the plants, obtained by a method of the invention. Contemplated part(s) of plants may be selected from the group consisting of: a fruit, a leaf, a root, a stem, pollen, an ovule, a cell, and a seed.

These plants of the invention can be characterized in that they display ZYMV and WMV resistance, may further comprise CMV resistance, and may comprise at least one further agronomic trait selected from: desired flesh color (e.g. orange, green, or white), ≥9.5° Bx, a length (i.e. distance from peduncle to blossom end of fruit; proximal to distal) to width ratio of less than about two to one (i.e. width to length ratio of ≥0.5), such as a length to width ratio of about one to one, and resistance to Powdery Mildew (PM) caused by Podosphaera xanthii. These plants can be selected from the F₁ or F₂ progeny, or from the steps of backcrossing and/or selfing the F₁ or F₂ progeny or from any subsequent selfing or backcross steps. Also comprised in the invention are the seeds of the above-mentioned plants. The invention further comprises the fruits, or part of fruits, of above-mentioned plants.

The invention further pertains to the melon lines and melon inbred lines obtained by the method of the invention, via multiple steps typical of plant breeding, including, but not limited to, an initial cross of two melon plants, at least one of which contains favorable alleles for the virus resistances described herein, recurrently selecting and self-pollinating plants in sequential generations (e.g. F1, F2, F3, . . . , Fn) after the cross, or backcrossing the F1, F2, backcross 1 (“BC1”), BC2, BC3, BC4, . . . BCn progeny to the recurrent parent, and optional selfing to produce homozygous lines. Alternatively, or in combination, the double haploid technique may be applied.

The invention further pertains to the hybrids, obtained by crossing the melon inbred lines of the invention with different melon inbred lines or elite lines. Also comprised in the invention are seeds of said hybrids.

The establishment of the proper introgression in offspring plants of the invention may be monitored at several steps (of the above mentioned method) by screening the genome of the plants for the presence of the resistance alleles defined herein. The population can be screened in a number of different ways. For instance, the population can be screened using a resistance assay as described above. Such assays are known in the art. Alternatively marker assisted selection can be used.

In embodiments of methods for detecting the presence of a marker in a melon plant, the method may also comprise the steps of providing an oligonucleotide or polynucleotide capable of hybridizing under stringent hybridization conditions to a nucleic acid sequence associated with said allele, or of a marker linked to said allele, contacting said oligonucleotide or polynucleotide with optionally digested genomic nucleic acid of a melon plant, and determining the presence of specific hybridization of said oligonucleotide or polynucleotide to said genomic nucleic acid. The method may also comprise RFLP analysis and/or DNA sequencing.

The method may be performed on a nucleic acid sample obtained from said melon plant, although in situ hybridization methods may also be employed. Alternatively, and in a further embodiment, the skilled person may, once the nucleotide sequence of the allele has been determined, design specific hybridization probes or oligonucleotides capable of hybridizing under stringent hybridization conditions to the nucleic acid sequence of said allele and may use such hybridization probes in methods for detecting the presence of an allele of the invention in a melon plant.

The present invention further relates to a melon seed designated ME8094, a sample of said seed having been deposited with the NCIMB, Aberdeen, Scotland under depositors reference ME8094 and NCIMB accession number 41653 and, a melon plant, or parts thereof, produced by growing said seed, and to pollen and ovules of the plant thus grown. The invention relates to a melon plant, or parts thereof, having all of the physiological and morphological characteristics of the melon plant grown from the deposited seed, to a tissue culture, such as a culture of cells of protoplasts from a tissue selected from the group consisting of leaves, pollen, embryos, roots, root tips, anthers, flowers, fruit, and seeds of regenerable cells, of a melon plant of line ME8094, wherein the tissue regenerates plants capable of expressing all the morphological and physiological characteristics of line ME8094. The invention further relates to a melon plant regenerated from said tissue culture, capable of expressing all the morphological and physiological characteristics of line ME8094.

The present invention further relates to a method for producing a hybrid melon seed comprising crossing a first inbred parent melon plant with a second inbred parent melon plant, or with another, different melon plant, and harvesting the resultant hybrid melon seed, wherein said first or second parent melon plant is the melon plant grown from the deposited seed. The present invention further relates to a hybrid melon seed produced by this method, to a hybrid melon plant, or parts thereof, subsequently produced by growing the hybrid melon seed as produced by the method, as well as melon seed subsequently produced by growing said hybrid melon plant and to a melon plant, or parts thereof, subsequently produced from said seed.

The present invention further relates to a method for producing a ME8094-derived melon plant, comprising: a) crossing a plant of line ME8094, a sample of said seed having been deposited with the NCIMB, Aberdeen, Scotland under accession number NCIMB 41653 and depositors reference ME8094, with a second melon plant to yield progeny melon seed; b) growing said progeny melon seed, under plant growth conditions, to yield said ME8094-derived melon plant. This method may optionally further comprise the step of: c) crossing said ME8094-derived melon plant with itself or another melon plant to yield additional ME8094-derived progeny melon seed; d) growing said progeny melon seed of step (c) under plant growth conditions, to yield additional ME8094-derived melon plants; e) repeating the crossing and growing steps of (c) and (d) from 0 to 7 times to generate further ME8094-derived melon plants.

The invention also pertains to a melon plant, or parts thereof, as disclosed herein, wherein the plant or parts thereof have been transformed so that its genetic material contains one or more transgenes operably linked to one or more regulatory elements.

Definitions

The term “melon” as used herein refers to plants of the gourd family that carry large and often round fruit having pulpy flesh and many seeds that are embedded within the flesh or fill the center of the fruit, belonging to different species in the family of Cucurbitaceae such as Cucumis melo L. (muskmelon), Cucumis sativus (cucumber), and Citrullus lanatus (watermelon). When reference is made to “melon” as used herein, plants of these melon species are referred to. The term includes reference to Cucumis melo L.

Cucumis melo L. (C. melo) includes both wild accessions as well as a large number of cultivars and is generally sub-divided into the subspecies agrestis and melo. The latter is then further sub-divided in the botanical varieties cantalupensis, chito, conomon, flexuosus, inodorus, momordica, reticulatus and texanus. It is believed that melon accession ME8094, represents an oriental pickling melon.

The term “Cucumis melo plant” as used herein refers to a plant of any variety of muskmelon as defined above. In certain embodiments, the term refers to muskmelon plants of the varieties Cucumis melo var. cantalupensis, Cucumis melo var. conomon, Cucumis melo var. reticulatus and Cucumis melo var. inodorus, such as for instance the cultivars or commercial types ‘Amarillo Oro’, ‘Sharlyn,’‘Cantaloupe’, ‘Casaba’, ‘Crenshaw’, ‘Earl's’ (Japanese Melon), ‘Galia’, ‘Honeyball’, ‘Honeydew’, ‘Jenny Lind’, ‘Ogen’, ‘Piel de Sapo’, green flesh ‘Rocky Ford’, ‘Santa Claus’, ‘Tendral’, Easter and Western Shipper, and ‘Yellow Canary’.

The term “family” indicates a taxonomic level below that of the order (i.e. the family Cucurbitaceae).

The term “firmness” indicates the force (kgf) needed to penetrate the rind using a digital handheld penetrometer.

The term “genus” indicates a taxonomic level below that of the family (i.e. the genus Cucumis or Citrullus).

The term “species” indicates a taxonomic level below that of the genus (e.g. Cucumis melo (muskmelon) or Citrullus lanatus (watermelon)).

The term “subspecies” indicates a taxonomic level below that of the species (e.g. Cucumis melo subsp. melo, or Citrullus lanatus subsp. vulgaris (watermelon)).

The term “variety”, indicates a varietas and its abbreviation “var.”, and refers to a botanical variety (a taxonomic level below that of the species or subspecies). As used herein, the term “variety” specifically is not equivalent with the term variety as defined in the UPOV treaty (the UPOV variety is herein equivalent to ‘accession’). Within the species of Cucumis melo, the term “Group” is often used when referring to the different varieties, and these terms are in this context equivalent and interchangeable. The following varieties are generally recognized in C. melo: The chito group (mango melon); the conomon group (Cucumis melo var. conomon; oriental pickling melon); the flexuosus group (Armenian cucumber); the inodorus group (Cucumis melo var. inodorus; casaba melon or honeydew); the reticulatus group (Cucumis melo var. reticulatus; synonyms: netted melon, nutmeg melon, American cantaloupe, false cantaloupe); and the cantalupensis Group (Cucumis melo var. cantalupensis; synonym: true cantaloupe or European cantaloupe).

The term “accession” denotes (a plant representing) the lowest taxonomical rank and thus it is equivalent to the term ‘variety’ as defined in the UPOV treaty and according to Rule 26(4) of the European Patent Convention. The term “cultivar” denotes a cultivated accession and is used herein to denote a plant having a biological status other than a “wild” status, which wild status indicates the original non-cultivated, or natural state of a plant or accession. The term “cultivar” includes, but is not limited to, semi-natural, semi-wild, weedy, traditional cultivar, landrace, breeding material, research material, breeder's line, synthetic population, hybrid, founder stock/base population, inbred line (parent of hybrid cultivar), segregating population, mutant/genetic stock, market class and advanced/improved cultivar. Examples of cultivars include such cultivated accessions as Charentais, Italian cantaloupe (from the cantalupensis Group); Galia, Ananas (from the reticulatus Group); Amarillo, Branco, Crenshaw, Honeydew Negro, Piel de Sapo, Rochet, Tendral, (from the conomon Group) oriental pickling melon, and Yellow Canary (from the inodorus Group).

The term “Brix” (“° Bx”) is used here to quantify the mass ratio of dissolved solids, such as sucrose, to water in a liquid. More specifically, a measurement of the Brix level of a melon fruit may be made according to methods well known in the art, for instance by use of a saccharimeter or refractometer. For instance, a measurement of 10° Bx corresponds to 10 grams of dissolved solids including sucrose per 100 grams of liquid.

The term “donor” is used to indicate the source of the hereditary material that confers resistance as defined herein. For instance, the ZYMV, WMV, and CMV resistance traits discussed in the present application originate from a donor melon plant designated as ME8094 (accession NCIMB 41653) or progeny thereof.

The term “crossing” as used herein refers to the fertilization of female plants (or gametes) by male plants (or gametes). The term “gamete” refers to the reproductive cell (egg or sperm) produced in plants by meiosis from a gametophyte and involved in sexual reproduction, during which two gametes of opposite sex fuse to form a zygote. The term generally includes reference to a pollen (including the sperm cell) and an ovule (including the ovum). Crossing therefore generally refers to the fertilization of ovules of one individual with pollen from another individual, whereas “selfing” refers to the fertilization of ovules of an individual with pollen from the same individual. Crossing is widely used in plant breeding and results in a mix of genomic information between the two plants equivalent to receiving homologous chromosomes from both the mother and the father. This will result in a new variety. Selfing of a homozygous plant will result in a genetically similar plant since there is no new genetic variation introduced.

When referring to crossing in the context of achieving the introgression of a genomic region or segment, the skilled person will understand that in order to achieve the introgression of only a part of a chromosome of one plant into the chromosome of another plant, it is required that random portions of the genomes of both parental lines will be recombined during the cross due to the occurrence of crossing-over events in the production of the gametes in the parent lines. Therefore, the genomes of both parents must be combined in a single cell by a cross, where after the production of gametes from said cell and their fusion in fertilization will result in an introgression event.

As used herein, the terms “introgressing”, “introgress” and “introgressed” refer to both a natural and artificial process whereby individual genes, chromosomal segments, or entire chromosomes are moved from one individual, species, variety or cultivar into the genome of another individual, species, variety or cultivar, by crossing those individuals, species, varieties or cultivars. In plant breeding, the process usually involves selfing or backcrossing to the recurrent parent to provide for an increasingly homozygous plant having essentially the characteristics of the recurrent parent in addition to the introgressed gene or trait.

The term “introgression” refers to the result of an introgression event.

The term “backcross” refers to the process wherein the plant resulting from a cross between two parental lines is repeatedly crossed with one of its parental lines, wherein the parental line used in the backcross is referred to as the recurrent parent. Repeated backcrossing results in replacement of genome fragments of the donor parent with those of the recurrent. Backcrossing methods can be used with the present invention to improve or introduce a characteristic into the inbred. The parental melon plant which contributes the gene for the desired characteristic is termed the nonrecurrent or donor parent. This terminology refers to the fact that the nonrecurrent parent is used one time in the backcross protocol and therefore does not recur. The parental plant to which the gene or genes from the nonrecurrent parent are transferred is known as the recurrent parent as it is used for several rounds in the backcrossing protocol. In a typical backcross protocol, the original inbred of interest (recurrent parent) is crossed to a second inbred (nonrecurrent parent) that carries the single gene of interest to be transferred. The resulting progeny from this cross are then crossed again to the recurrent parent and the process is repeated until a plant is obtained wherein essentially all of the desired morphological and physiological characteristics of the recurrent parent are recovered in the converted plant, in addition to the single transferred gene from the nonrecurrent parent.

The term “selfing” refers to the process of self-fertilization wherein an individual is pollinated or fertilized with its own pollen. Repeated selfing eventually results in homozygous offspring.

As used herein, the term “homozygous” means a genetic condition existing when identical alleles reside at corresponding loci on homologous chromosomes.

As used herein, the term “heterozygous” means a genetic condition existing when different alleles reside at corresponding loci on homologous chromosomes.

The term “recombination” or “to recombine” refers to the exchange of information between two homologous chromosomes during meiosis. In a “recombinant” plant, DNA that is originally present at a specific location within the chromosome, e.g. linked to a gene/locus, is exchanged for DNA from another plant (i.e. maternal for paternal or vice versa). In order to exchange only the required material, and maintain the valuable original information on the chromosome as much as possible, two flanking crossover or recombination events will usually be required. In a double recombinant this exchange has taken place on both sides of a gene/locus. One way to find such a double recombinant, is to screen a population of F2-plants. This population has to be large, since double recombination occurs with limited frequency. Alternatively, double recombinants can be the result of subsequent backcrossing. The frequency of double recombination is the product of the frequencies of the single recombinants (e.g. a recombinant in a 10 cM area can be found with a frequency of 10%, double recombinants are found with a frequency of 10%×10%=1%).

As used herein, the term “progeny” means (a) genetic descendant(s) or offspring.

As used herein, the term “population” means a genetically heterogeneous collection of plants derived from a shared, common genitor.

A “recombination event” refers to a mitotic or meiotic crossing-over event, as well as a transgenic event.

As used herein, the color of the flesh of a melon fruit may be defined by comparison with a reference color chart, such as the RHS color chart, as is known in the art. In certain embodiments the flesh color may be termed “orange” and defined as corresponding to 9A-35B or 40A-44C as denoted by the RHS color chart.

As used herein, the term “hybrid” means any offspring of a cross between two genetically unlike individuals, more generally the term refers to the cross between two (elite or inbred) breeding lines which will reproduce true to the parent from seed.

The term “breeding line”, as used herein, refers to a line of a cultivated melon having commercially valuable or agronomically desirable characteristics, as opposed to wild varieties or landraces that are the result of natural selection. The term includes reference to an elite breeding line or elite line, which represents an essentially homozygous, usually backcrossed and inbred, line of plants used to produce (commercial) F₁ hybrid seeds. Agronomically desirable characteristics include, but are not limited, to disease resistance, insect resistance, valuable fruit characteristics, yield, etc. A breeding line is typically an inbred line, and may be an elite line.

As used herein, the term “pure inbred” or “inbred” refers to a substantially homozygous plant or plant line obtained by repeated selfings.

As used herein, the term “allele(s)” means any of one or more alternative forms of a locus or gene, all of which alleles relate to at least one trait or characteristic. In a diploid cell or organism, the two copies of a gene occupy corresponding loci on a pair of homologous chromosomes. Each copy may be a distinct allele.

A “gene” is defined herein as a hereditary unit (often indicated by a sequence of DNA) that occupies a specific location on a chromosome and that contains the genetic instruction for a contribution to potential phenotypic characteristics or trait in a plant.

A “locus” is defined herein as the position that a given gene occupies on a chromosome of a given plant species.

Similar to the genetic unit “gene”, on which the phenotypic expression depends on a large number of factors that cannot be predicted, the genetic unit “QTL” denotes a region of the genome that is related to a phenotypically quantifiable trait.

The term “natural genetic background” is used herein to indicate the original genetic background of an allele or QTL. Conversely, a method that involves the transfer of DNA comprising the allele or QTL, or a part thereof that confers the specific characteristic resident in the allele or QTL, to the same position on the corresponding chromosome of another melon line or variety, will result in that allele or QTL, or said part thereof, not being in its natural genetic background.

As used herein, the term “linkage group” refers to all of the genes or genetic traits that are located on the same chromosome. Within the linkage group, those loci that are close enough together will exhibit linkage in genetic crosses. Since the probability of crossover increases with the physical distance between genes on a chromosome, genes whose locations are far removed from each other within a linkage group may not exhibit any detectable direct linkage in genetic tests. The genes are ‘indirectly linked’, via intermediately positioned loci. The term “linkage group” is mostly used to refer to genetic loci that exhibit linked behavior in genetic systems where chromosomal assignments have not yet been made. Thus, in the present context, the term “linkage group” is synonymous to (the physical entity of) a chromosome.

As used herein, the terms “molecular genomic marker,” “molecular marker” or “marker” refer to an indicator that is used in methods for visualizing differences in characteristics of nucleic acid sequences. Examples of such indicators are restriction fragment length polymorphism (RFLP) markers, amplified fragment length polymorphism (AFLP) markers, single nucleotide polymorphisms (SNPs), insertion/deletion (INDEL) mutations, microsatellite markers (SSRs), sequence-characterized amplified regions (SCARs), cleaved amplified polymorphic sequence (CAPS) markers or isozyme markers or combinations of the markers described herein which defines a specific genetic and chromosomal location. DNA sequencing may also be employed to determine the allele present at a given marker of interest. Molecular genomic markers are used in the well known processes of MAB (marker assisted backcrossing) and MAS (marker assisted selection), wherein the speed and efficiency of the breeding process can be greatly enhanced using technical information on the position of the gene or allele of interest.

The term “transformed” is used herein as a synonym for the transfer of isolated and cloned genes into the DNA, usually the chromosomal DNA or genome, of another organism by genetic engineering techniques, usually by the aid of a vector or other genetic transformation system.

The terms “resistant” and “resistance” encompass both partial and full resistance to infection. A pathogen susceptible melon plant may either be non-resistant or have low levels of resistance to infection by the pathogen. Resistance also includes a symptomless-carrier, but generally relates to the absence, or at least a low titer, of virus particles in the plant, as for instance observable with antibodies, upon infection. In certain embodiments, plants of the invention exhibit resistance to the diseases essentially as exhibited by accession ME8094 as well as one or more other parental lines in their pedigree(s).

The term “pathogen-susceptible recipient melon plant” is used herein to indicate a melon plant that is to receive DNA obtained from a donor melon plant that comprises the pathogen-resistance allele. Said pathogen-susceptible recipient melon plant may or may not already comprise one or more alleles for (the same or other) resistance, in which case the term indicates a plant that is to receive an additional resistance allele.

As used herein, the term “plant part” indicates a part of the melon plant, including organelles, single cells and cell tissues, such as plant cells that are intact in plants, cell clumps and tissue cultures from which melon plants can be regenerated. Examples of plant parts include, but are not limited to, single cells, protoplasts, and tissues from pollen, ovules, leaves, embryos, roots, root tips, anthers, flowers, fruits, stems shoots, and seeds; as well as pollen, ovules, leaves, embryos, roots, root tips, anthers, flowers, fruits, stems, shoots, scions, rootstocks, seeds, protoplasts, calli, and the like.

As used herein, the term “Zucchini yellow mosaic virus” abbreviated as “ZYMV” refers to an aphid-borne potyvirus that affects all cucurbits including pumpkins, squashes, vegetable marrows, courgettes, melons, watermelons, cucumbers, gherkins and various gourds. The effects are severe leaf mosaic, yellowing and eventually “shoestring” symptoms in the leaves. The fruits are stunted, twisted and deformed by raised protuberances, which make them unmarketable. In cultivated crops plants cease producing marketable fruits within 1-2 weeks of infection and serious financial losses can occur.

As used herein, the term “Watermelon mosaic virus” abbreviated as “WMV” (formerly known as “WMV-2”) is also an aphid-transmitted potyvirus that can infect and produce symptoms on all commercially grown cucurbits. This causes milder symptoms on the foliage of most infected plants like squash, and growers have seen a lessening of foliar symptoms following fertilization. Fruit distortion and color breaking are still a problem on varieties like yellow straight-neck squash. The host range for WMV-2 is not limited to cucurbits, thus opening the possible overwintering of this virus in several leguminous species such as clover. Mixed infections of cucurbits with CMV and WMV-2 are common by the end of the season.

As used herein, the term “Papaya Ringspot Virus” abbreviated as “PRSV” (formerly known as “WMV-1”) is aphid transmitted, and infection is limited to cucurbits. This virus is capable of infecting all commercial cucurbit crops. The foliage of affected plants shows strong mosaic, distortion, and deep leaf serration. Fruits are also malformed with knobby overgrowth.

As used herein, the term “Cucumber mosaic virus” abbreviated as “CMV” is a plant pathogenic virus in the family Bromoviridae. It is the type member of the plant virus genus, Cucumovirus. This virus has a worldwide distribution and a very wide host range. In fact it has among the widest host range of any known plant virus (191 hosts in 40 families). It can be transmitted from plant to plant both mechanically by sap and by aphids in a stylet-borne fashion. It can also be transmitted in seeds and by the parasitic weeds, Cuscuta sp. (dodder). Since CMV was first recognized it has been found to infect a great variety of other plants, including other vegetables such as squash, melons, peppers, beans, tomatoes, carrots, celery, lettuce, spinach and beets, various weeds and many ornamentals and bedding plants. Symptoms seen with this virus include leaf mosaic or mottling, yellowing, ringspots, stunting, and leaf, flower and fruit distortion.

DEPOSIT INFORMATION

A deposit of C. melo line ME8094 which is disclosed herein above and referenced in the claims, was made with NCIMB, Ferguson Building, Craibstone Estate, Bucksburn, Aberdeen, AB21 9YA, Scotland, U.K. The date of deposit was Sep. 4, 2009 and the accession number for those deposited seeds of melon line ME8094 is NCIMB Accession No. 41653. All restrictions upon the deposit have been removed, and the deposit is intended to meet all of the requirements of 37 C.F.R. § 1.801-1.809. The deposit will be maintained in the depository for a period of 30 years, or 5 years after the last request, or for the effective life of the patent, whichever is longer, and will be replaced if necessary during that period.

Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the invention, as limited only by the scope of the appended claims.

All references cited herein are hereby expressly incorporated herein by reference.

EXAMPLES Example 1: Genetic Markers of C. melo Linkage Groups 02, 11, and 12

A consensus genetic map was developed for C. melo comprising genetic markers on chromosomes (i.e. “linkage groups”) 1-12. A melon genetic map is diagrammed in FIG. 1 and markers are listed in Table 4 for chromosomes 02, 11, and 12 including those found to be linked to trait(s) conferring resistance to WMV, ZYMV, and CMV.

TABLE 4 Genetic markers on melon chromosomes linked to virus resistance traits of interest. Map position Marker name Chromosome (cM) NU0218625 2 0 NU0243780 2 0 NU0218305 2 2.005023473 NU0220431 2 2.260671264 NU0218248 2 3.242407591 CMBR041 2 3.264408637 NU0218808 2 3.403622419 NU0218497 2 3.887811556 NU0218113 2 3.965525472 NU0244013 2 4.04473782 NU0244734 2 4.06540191 NU0220855 2 4.097716126 NU0244741 2 4.097716126 NU0220997 2 4.262198996 NU0220034 2 5.70260578 NU0220178 2 5.739450718 NU0218179 2 5.739450718 NU0243740 2 5.739450718 NU0218531 2 5.739450718 NU0244228 2 6.439646176 NU0219402 2 8.005689695 NU0220130 2 8.201296581 NU0219191 2 8.46671327 NU0219483 2 8.46671327 NU0220928 2 8.46671327 NU0218758 2 8.870936634 NU0243353 2 10.31160741 NU0220646 2 10.4013544 NU0220793 2 10.87913017 NU0243722 2 10.87913017 NU0220647 2 11.5186551 NU0243479 2 13.54962773 NU0218211 2 17.53850024 NU0244702 2 19.26707387 NU0244778 2 19.28565793 NU0218156 2 22.52068613 NU0219009 2 23.73349775 NU0244019 2 23.90571157 NU0219243 2 26.46334624 NU0244631 2 26.50123545 NU0218641 2 27.31597847 NU0219769 2 27.31597847 NU0220607 2 27.31597847 NU0221028 2 27.31597847 NU0244521 2 27.31597847 NU0244557 2 27.35742402 NU0218847 2 27.4327107 NU0219284 2 29.07702559 NU0220497 2 31.36395523 NU0220373 2 33.319037 NU0220671 2 33.319037 NU0221012 2 33.319037 NU0218600 2 35.34813167 NU0219157 2 36.05158803 NU0218325 2 37.00118133 NU0220688 2 37.00118133 NU0220575 2 37.00118133 NU0218570 2 40.44668981 NU0219353 2 40.44668981 NU0218794 2 42.79509072 NU0218957 2 44.3589836 NU0243402 2 44.3589836 NU0220299 2 44.59619893 NU0219474 2 45.97152125 NU0243330 2 46.16907705 NU0243691 2 46.16907705 NU0219497 2 47.67357163 NU0220778 2 47.67357163 NU0220341 2 48.78886347 NU0220623 2 48.78886347 NU0243559 2 48.78886347 NU0243262 2 48.80075654 NU0244117 2 49.69564747 NU0243516 2 49.72408802 NU0244258 2 49.72408802 NU0218783 2 50.08465281 NU0220057 2 50.15524031 NU0220378 2 50.24974769 NU0221022 2 51.7153129 NU0243544 2 51.7153129 NU0218553 2 52.34831859 NU0219511 2 52.59656731 NU0220230 2 52.81618911 NU0220799 2 52.85478221 NU0218033 2 53.16910559 NU0218250 2 53.16910559 NU0219019 2 53.16910559 NU0219150 2 53.16910559 NU0220902 2 53.16910559 NU0218440 2 53.98983146 NU0219260 2 53.98983146 NU0243343 2 55.46780895 NU0244057 2 56.41141875 NU0218263 2 56.68725237 NU0219294 2 56.91002694 NU0218782 2 57.07230164 NU0219961 2 57.07230164 NU0218391 2 57.09555749 NU0219210 2 57.09555749 NU0219737 2 57.09555749 NU0220030 2 57.09555749 NU0243709 2 57.09555749 NU0220988 2 57.09555749 NU0219065 2 57.24368788 NU0243918 2 57.24368788 SE0341 2 61.42827898 NU0218418 2 63.59125892 NU0218939 2 63.59125892 NU0219989 2 63.67652446 NU0219146 2 63.8882434 NU0220101 2 64.07617266 NU0219616 2 64.55779844 NU0218061 2 65.36267604 NU0220948 2 65.64163136 NU0220052 2 66.48327011 NU0218189 2 68.87889185 NU0218383 2 69.69643795 NU0218546 2 70.10661241 NU0218893 2 70.10661241 NU0218721 2 77.54261021 NU0220876 2 77.54261021 NU0243799 2 77.54261021 NU0218174 2 77.54479389 NU0220375 2 77.54479389 NU0219901 2 79.08012076 NU0220356 2 79.08012076 NU0220970 2 79.08012076 NU0221047 2 79.08012076 NU0243606 2 79.08012076 NU0244619 2 79.08012076 NU0218669 2 79.69358302 NU0218746 2 79.69358302 NU0219744 2 79.69358302 NU0220859 2 79.69358302 NU0220476 2 80.09862541 NU0220355 2 80.18444824 NU0218140 2 80.69070778 NU0243345 2 80.69070778 NU0243772 2 80.69070778 NU0219030 2 80.69070778 NU0243554 2 80.69070778 NU0219481 2 80.76165418 NU0220783 2 80.76165418 NU0218199 2 80.76165418 NU0218904 2 81.51930238 NU0218979 2 81.52021354 NU0218220 2 81.91470526 NU0220314 2 83.53806571 NU0243560 2 83.53806571 NU0220810 2 86.05056343 NU0220771 2 86.32269617 NU0220659 2 86.32269617 NU0219017 2 87.37190381 NU0243573 2 89.62806106 NU0218877 2 89.92424416 NU0220936 2 89.92782739 NU0218353 2 90.01309293 NU0218717 2 90.20317144 NU0219021 2 92.19321242 NU0243299 2 92.92763465 NU0220226 2 92.92763465 NU0218628 2 95.16332824 NU0218658 2 95.16388553 NU0221096 2 95.88501249 NU0220530 2 96.27853586 NU0220805 2 96.28786843 NU0219207 2 97.2542964 NU0218356 2 97.35009928 NU0220927 2 97.35009928 NU0218624 2 97.51390043 NU0243515 2 98.19441601 NU0219540 2 98.49965899 NU0219493 2 98.83192395 NU0219882 2 98.87356709 NU0221091 2 98.87412438 NU0220994 2 98.87523896 NU0243824 2 98.87523896 NU0220200 2 98.91708695 NU0218640 2 98.91906823 NU0218505 2 98.92164782 NU0218203 2 100.3382136 NU0219047 2 102.664891 NU0218842 2 103.622176 NU0220558 2 104.2237891 NU0220620 2 104.9671526 NU0220993 2 105.1483269 NU0218138 2 106.3776567 NU0219543 2 107.0508151 NU0220488 2 107.2270656 NU0243788 2 107.2270656 NU0219082 2 109.9694299 NU0220779 2 111.6942303 NU0220016 2 111.7005636 NU0220087 2 111.7005636 NU0220264 2 111.8560636 NU0243948 2 111.8560636 NU0220430 2 112.2371728 NU0218830 2 114.0145725 NU0219228 2 115.921417 NU0218389 2 117.9810865 NU0244618 2 117.9810865 NU0219006 2 118.453265 NU0219836 2 118.453265 NU0220218 2 118.9817073 NU0218169 2 121.468814 NU0221058 2 122.1873339 NU0243414 2 122.8824587 NU0218596 2 123.0559663 NU0218826 2 123.2670299 NU0219966 2 123.695847 NU0218446 2 125.6573116 NU0243702 2 125.8159286 NU0220458 2 125.9749803 NU0220764 2 125.9761989 NU0218720 2 126.0726332 NU0220270 2 126.2916364 NU0219034 2 126.2916364 NU0219225 2 126.2916364 NU0219249 2 126.2916364 NU0220959 2 126.2916364 NU0220964 2 126.2916364 NU0243940 2 126.2916364 NU0244513 2 126.2916364 NU0244537 2 126.2916364 NU0220054 11 0 NU0221092 11 0.579491077 NU0243725 11 0.676851956 NU0243674 11 1.181352896 NU0220286 11 1.251924704 NU0220920 11 1.255924704 NU0220069 11 1.309838516 NU0243719 11 2.551786372 NU0219128 11 3.280432909 NU0218591 11 4.468607303 NU0218714 11 5.392246359 NU0220796 11 5.614301648 NU0218738 11 6.025904953 NU0218409 11 6.025904953 NU0243450 11 7.440650256 NU0219374 11 8.375428163 NU0218820 11 8.64589173 NU0220434 11 10.10512685 NU0219761 11 13.2046766 NU0219093 11 13.84374788 NU0219278 11 13.95924788 NU0220359 11 13.95924788 NU0219222 11 15.17341133 NU0218219 11 16.9324201 NU0220289 11 17.00523634 NU0218365 11 17.08223634 NU0219403 11 17.08223634 NU0219113 11 17.11473172 NU0221042 11 17.97523187 NU0220691 11 21.34786778 NU0220165 11 21.71642696 NU0218764 11 21.73355638 NU0218299 11 22.4309501 CmG3478 11 22.4309501 NU0219414 11 22.83068043 NU0219288 11 23.06973484 NU0219419 11 24.15879707 NU0244606 11 25.6355839 NU0218483 11 26.89140175 NU0218544 11 26.89578504 NU0218959 11 26.89578504 NU0218902 11 27.21507391 NU0218954 11 27.21507391 NU0220821 11 27.21507391 NU0244632 11 27.21507391 NU0219830 11 27.85759349 NU0218768 11 28.86227875 NU0221100 11 28.86327875 NU0219539 11 28.87557456 SE723 11 29.92114575 NU0218070 11 33.40862868 NU0220134 11 35.76768479 NU0220967 11 35.80618479 NU0220486 11 37.94141179 NU0219106 11 38.96729613 NU0218654 11 40.05361767 NU0219300 11 40.14572756 NU0218916 11 40.92381096 NU0218229 11 41.07298503 NU0219099 11 41.07298503 NU0219188 11 41.65192069 NU0219801 11 41.66548076 NCMEL008383076 11 41.89 NU0218433 11 42.20446289 NU0220960 11 42.37048076 NU0218933 11 42.41083198 NCMEL008383077 11 43.437 NU0218595 11 43.62110094 NU0218967 11 43.63891132 NU0218656 11 44.62607776 NU0218779 11 44.62607776 NU0220729 11 44.62607776 NCMEL008383075 11 45.79 NCMEL008383078 11 46.62 NU0221009 11 46.99340816 NU0219002 11 47.05320136 NU0219293 11 47.94879191 NU0220333 11 47.94879191 NU0218835 11 49.00993938 NU0244142 11 51.01781843 NU0218132 11 52.59788198 NU0218032 11 53.43954174 NU0218745 11 53.43954174 NU0219710 11 53.43954174 NU0218951 11 53.47802543 NU0218514 11 53.55499282 NU0219090 11 54.60895211 NU0220889 11 54.60895211 NU0220093 11 56.47533558 NU0219542 11 56.64158558 NU0219400 11 56.64308558 NU0243680 11 56.64308558 NU0218709 11 58.40296509 NU0218218 11 59.92977682 NU0219398 11 59.92977682 NU0244676 11 60.47061523 NU0219055 11 60.51306833 NU0243512 11 61.56346641 NU0218204 11 61.68875818 cc10099 11 61.68875818 NU0218968 11 63.02817506 NU0220157 11 64.93671828 NU0219383 11 65.47470549 cc10068 11 65.93661215 NU0219583 11 66.28255663 NU0218958 11 68.24652465 NU0219810 11 68.24652465 NU0218770 11 68.29128671 NU0221035 11 68.67305663 NU0219652 11 68.90655663 SE899 11 68.90655663 NU0220829 11 69.38877236 NU0218382 11 69.38877236 NU0219639 11 69.38877236 NU0218676 11 72.90585647 NU0218092 11 72.90585647 NU0218924 11 74.29384966 NU0244357 11 74.29384966 NU0244370 11 74.32208492 NU0218909 11 74.34956443 NU0218784 11 74.55728442 NU0219846 11 74.55728442 NU0218786 11 75.10634538 NU0218898 11 75.27259481 NU0220496 11 76.50873929 NU0220610 11 76.53636781 NU0221008 11 76.64786781 NU0219742 11 76.78559315 NU0221014 11 76.82273929 NU0220618 11 77.11334843 NU0220490 11 77.17143096 NU0220250 11 77.18339337 NU0219563 11 77.68620247 NU0218792 11 78.60068556 NU0220322 11 78.61224748 NU0220834 11 79.15342413 NU0219586 11 79.19192413 NU0219609 11 79.51510282 NU0219770 11 80.30342396 NU0220053 11 80.30342396 NU0218381 11 85.17084048 NU0218827 11 85.17084048 NU0243884 11 85.17741568 NU0219608 11 85.18545202 NU0219718 11 85.18545202 NU0218825 11 85.97190691 NU0219151 11 88.05836653 NU0220794 11 88.42669556 NU0218117 11 88.79685958 NU0219370 11 88.83425114 NU0243739 11 91.54378039 NU0244493 11 91.54378039 NU0218536 11 92.03358083 NU0220903 11 92.03358083 NU0243879 11 92.03358083 NU0218642 11 92.51885845 NU0218304 11 92.74403775 NU0220837 11 94.00804258 NU0220463 11 94.31720706 NU0220183 11 95.89334078 NU0218510 11 96.51229354 NU0220347 11 96.74184742 CmCT160a + b 11 98.36261107 NU0218578 11 98.36261107 NU0243558 11 99.1399082 NU0218253 11 99.4396658 NU0218270 11 99.4396658 NU0243423 11 99.4396658 NU0219914 11 100.3864252 NU0219773 11 102.7694017 NU0219778 11 102.7694017 NU0219724 11 102.9062938 NU0243301 11 103.6458855 NU0218969 11 103.992192 NU0243936 11 106.2476904 NU0243959 11 106.2597459 NU0219521 11 107.7868211 NU0219584 11 107.9680882 NU0221076 11 107.9680882 NU0219407 11 108.8878396 NU0219697 11 109.0170254 NU0218804 11 109.0170254 NU0218518 11 109.0590254 NU0220203 11 109.0590254 NU0218349 11 109.807591 NU0219661 11 114.4052332 NU0243718 11 114.5233688 NU0243425 11 114.6985556 NU0244342 11 116.3244118 NU0219291 11 116.542881 NU0218099 11 116.7661255 NU0219663 11 116.8728498 NU0219135 11 116.8728498 NU0219731 11 116.8728498 NU0218712 11 117.1195388 NU0218111 11 117.1195388 NU0218280 11 117.1195388 NU0218707 11 117.1195388 NU0219247 11 117.1195388 NU0219537 11 117.1195388 NU0243774 11 117.1195388 NU0219487 11 119.2967146 NU0218655 11 121.8943271 NU0218406 11 122.2483386 NU0244045 11 122.2483386 NU0220139 11 122.2483386 NU0218878 11 122.4091346 SE927 11 122.5797701 NU0243947 11 122.6028634 NU0219393 11 122.8854578 NU0218289 11 122.8854578 NU0220614 11 124.9158327 NU0244789 11 124.9158327 NU0243339 11 126.5084681 NU0243829 11 126.5129674 NU0243988 11 126.8156232 NU0219430 11 133.3776428 NU0219397 11 138.027749 NU0221082 11 139.4296606 NU0218873 12 0 NU0219732 12 0.524202775 NU0243348 12 3.475832734 NU0219253 12 9.612296569 NU0219368 12 10.02661869 NU0243273 12 10.02661869 NU0218397 12 10.19352794 NU0220542 12 10.19352794 NU0220640 12 10.19352794 NU0220164 12 11.66636775 NU0220298 12 11.66636775 NU0220815 12 11.66636775 NU0221084 12 13.44515144 NU0218338 12 13.44515144 NU0218681 12 15.28711456 NU0219647 12 17.52023559 NU0218777 12 17.52146696 NU0218921 12 19.91221103 NU0218108 12 22.89123568 NU0243668 12 23.7542249 NU0243767 12 23.7542249 NU0219517 12 28.68748661 NU0219050 12 29.95460323 NU0219834 12 29.96041247 NU0220934 12 29.96041247 NU0218053 12 29.96041247 NU0244550 12 29.96041247 NU0219654 12 31.74397834 NU0220999 12 31.74397834 NU0243817 12 31.74397834 NU0218055 12 31.74397834 NU0219615 12 31.74397834 NU0221081 12 31.92482213 NU0218605 12 32.7086158 NU0218931 12 32.94779845 NU0218994 12 32.94779845 NU0243783 12 32.94779845 NU0219820 12 33.1869811 NU0218475 12 34.15754871 NU0243561 12 34.46188978 NU0219343 12 34.76499704 NU0219170 12 35.48163568 NU0218834 12 39.61066417 NU0220916 12 39.6270824 NU0243358 12 39.77151577 NU0218362 12 39.77151577 NU0218390 12 39.77151577 NU0243625 12 39.77199762 NU0218620 12 39.81488236 NU0220929 12 39.81488236 NU0218760 12 39.81488236 NU0218816 12 39.81488236 NU0220968 12 39.81488236 NU0219743 12 39.81970087 NU0243361 12 40.1855847 NU0218432 12 40.34025886 NU0219973 12 40.34025886 NU0219324 12 40.39846406 NU0219010 12 41.38733049 NU0243344 12 41.38733049 NU0218477 12 41.58191969 NU0218928 12 41.58191969 NU0219184 12 42.24060998 NU0220120 12 42.24060998 NU0244176 12 42.24060998 NU0219714 12 43.37621994 NU0219907 12 43.80825073 NU0243527 12 44.25702765 NU0219627 12 44.30905098 NU0219686 12 44.30905098 NU0220145 12 44.47221721 NU0218323 12 44.47221721 NU0218396 12 44.47221721 NU0219827 12 44.47221721 NU0243381 12 44.47221721 NU0243695 12 44.47221721 NU0218796 12 44.47221721 NU0219332 12 44.47221721 NU0220980 12 45.87976958 NU0220014 12 46.05091155 NU0220809 12 46.05091155 NU0218617 12 46.36834089 NU0219948 12 46.46036662 NU0220836 12 46.88602776 SE857 12 46.90401957 cc10056 12 47.50653131 NU0219404 12 47.50653131 NU0221005 12 47.50653131 NU0243365 12 47.50653131 NU0243469 12 47.50653131 NU0218164 12 48.4192602 NU0243717 12 48.4192602 NU0219382 12 49.45362973 NU0219891 12 49.45362973 NU0244674 12 49.45362973 NU0219320 12 49.58286753 NU0218516 12 49.58286753 CmG3492 12 49.60712983 NU0220254 12 49.64551961 NU0218668 12 49.6520651 CmG3822 12 49.65861059 NU0218984 12 49.65861059 NU0218254 12 49.65861059 NU0218791 12 49.65861059 NU0244060 12 49.65861059 NU0218859 12 51.42643529 NU0218074 12 51.87481232 NU0218735 12 51.87558896 NU0243397 12 51.87558896 NU0244210 12 51.87558896 NU0244480 12 51.87558896 NU0219352 12 52.14772471 NU0218603 12 53.62216566 NU0220702 12 53.8257582 NU0220361 12 53.86087599 NU0220773 12 53.86087599 NU0220144 12 54.5470543 NU0220484 12 55.17212525 NU0218828 12 55.17212525 NU0220091 12 55.89263411 NU0220249 12 56.94278853 NU0218540 12 58.13043392 NU0219454 12 58.13043392 NU0220758 12 59.8021111 NU0218771 12 59.99619355 NU0221010 12 60.07641546 NU0220188 12 60.21631574 NU0219706 12 60.40264595 NU0219704 12 60.76231733 NU0243507 12 61.60966718 NU0219796 12 62.24884912 NU0218467 12 63.42114857 NU0244654 12 63.4973667 NU0220433 12 63.52405869 NU0219410 12 63.53478364 NU0218192 12 63.53478364 NU0220148 12 65.40508157 NU0218175 12 65.40508157 NU0220384 12 65.56483985 NU0220811 12 65.56483985 NU0220184 12 66.44064295 NU0218120 12 66.87160823 NU0220204 12 66.87160823 NU0220401 12 67.28760394 NU0218344 12 67.28760394 NU0219875 12 70.39184496 NU0220940 12 70.47935274 NU0243971 12 70.47935274 NU0219723 12 70.52096181 NU0220795 12 71.34158681 NU0220354 12 71.81858524 NU0220657 12 71.81858524 NU0218296 12 74.36821732 NU0218348 12 74.61584889 NU0220594 12 74.61584889 NU0220923 12 75.60974611 NU0219896 12 75.8009085 NU0219204 12 75.87585812 NU0218883 12 75.88487683 NU0220966 12 76.6413981 NU0221040 12 77.17908761 NU0218780 12 77.17908761 CMBR058 12 77.43721738 NU0218287 12 77.56847415 NU0220734 12 77.56847415 NU0220151 12 77.56847415 NU0220622 12 77.56847415 NU0220725 12 77.56919958 NU0218705 12 77.77438134 NU0220591 12 77.77438134 NU0220306 12 79.29603953 NU0220865 12 79.52895166 NU0244700 12 79.52895166 NU0221018 12 79.84326339 Pm-2-con 12 80.32536277 Pm-2-R1 12 80.32536277 Pm-2-R2 12 80.32536277 Pm-2-R3 12 80.32536277 NU0218345 12 81.09801162 NU0219954 12 81.22002347 NU0220800 12 81.59372961 NU0218141 12 81.68196514 NU0219431 12 82.47150128 NU0220283 12 82.62014277 NU0244671 12 82.62014277 NU0219558 12 83.68151507 CMBR150 12 84.16843971 NU0218922 12 84.79950189 NU0218035 12 86.03156406 NU0219376 12 86.03156406 NU0244678 12 86.03156406 NU0219317 12 86.60269155 NU0218960 12 86.62642229 NU0220716 12 86.76049154 NU0218619 12 89.72644298 NU0219163 12 90.03826065 NU0218328 12 90.36418407 NU0219668 12 90.36418407 cc10051 12 90.56456327 NU0220141 12 90.76132908 NU0219043 12 91.23766493 NU0219970 12 91.23766493 NU0218700 12 92.66787676 NU0219185 12 93.07539745 NU0220882 12 93.25619114 NU0220913 12 93.80765241 NU0218119 12 93.86462238 NU0219459 12 94.39020904 NU0243764 12 97.11606425 CMBR040 12 97.96302974 CMBR097 12 97.96302974 NU0218666 12 98.21505968 NU0243585 12 98.21505968 NU0220517 12 98.29095818 NU0220639 12 98.29095818 CMBR077 12 98.53795852 NU0244051 12 98.9983828 NU0243754 12 100.2779543 NU0244225 12 100.7574383 NU0220872 12 100.9120098 CmG4837 12 102.1735532 NU0218837 12 103.9529945 NU0219411 12 104.0647791 NU0244425 12 104.5530428 NU0219264 12 105.1400743 NU0220252 12 105.5023022 NU0220933 12 106.2819298 NU0220802 12 106.2864188 NU0218824 12 106.2889416 NU0220833 12 106.6425556 NU0219007 12 106.6435556 NU0220146 12 106.6435556 NU0220450 12 108.8459907 NU0220509 12 108.8459907 NU0218946 12 109.1485385 NU0219131 12 109.1485385 NU0218488 12 109.2086222 NU0219168 12 109.2235385 NU0243533 12 109.3717208 NU0218464 12 109.3717208 NU0219072 12 109.3717208 NU0243351 12 109.6608628 NU0220720 12 109.6608628 NU0218136 12 110.4789252 NU0219145 12 110.559225 NU0218444 12 110.5675799 NU0220473 12 110.6065711 NU0220525 12 110.6090117 NU0218637 12 111.0582739 NU0219524 12 111.4939413 NU0220278 12 111.5098435 NU0220061 12 111.6205503 NU0221056 12 111.6397884 NU0218542 12 111.6397884 CmG5043 12 111.6521056 NU0219504 12 111.6658928 NU0220893 12 111.6694187 NU0220319 12 111.8025751 NU0244391 12 112.0925751 NU0219515 12 112.0925751 NU0219390 12 112.6912168 NU0219463 12 112.6912168

Markers listed in Table 4 may be utilized for instance via marker assisted selection (MAS) to identify melon plants comprising resistance to one or more of WMV, ZYMV, and CMV, among other viruses, for instance comprising such virus resistance trait(s) introgressed from virus resistant donor lines such as ME8094 (NCIMB 41653) or other virus resistance donor lines. Associated SNP and sequence information for selected melon virus resistance QTL is found in Table 5.

TABLE 5 SNP and sequence information for selected genetic markers linked to melon virus resistance (SEQ ID NOs: 1-39). Allele of Allele of Abbre- Map resistance suscep- Marker via- Chromo- Position donor tible name tion some (cM) source parent DNA Sequence NU0219106 Z/W 11  38.96729613 AA TT TTAATTTAAAATATGATCAGAACATCAATTGACAAA QTL 11 TTCTGAATACTATACTTGCACATT[A/T]CCTTCCATAC AAGAAAATATGTGGAACTTCACTCATGGTAGATTCA CATATATATAACTA (SEQ ID NO: 1) NU0218916 Z/W 11  40.92381 CC AA CCTGCCATGGCACCTACTCGCTGAAAGCAATGCTCC QTL 11 CCACAACAATGCCTTGTCATCAGG[A/C]GCTACATCC ATCGATTTCGCTATGTCAAAGGCTTTATCTAGCTCCC CAGATCGAGCTAGC (SEQ ID NO: 2) NU0219099 Z/W 11  41.07299 CC TT GTGGCTGCAGGATTTTATTTCAGGTACAAAACAATG QTL 11 TCTCTTGTCTCATATACGAACTTA[T/C]GTCCAGCCTC CAAATTCGGCACAAGCCAGATTGGCTTATCAGTTAG CACCATTTAAAGAC (SEQ ID NO: 3) NCMEL00 Z/W  41.89 CC AA GAGCCCATGACAAGATTCCCTCGCCAAAAGATATGT 8383076 QTL 11 TAATAACAAAGTAAANTTAANTAC[A/C]GAAATCAT TTTCTAAAGTTGAAAAACTAAAATCGATGCTTTAAA AATACCAAAATCAAAA (SEQ ID NO: 36) NCMEL00 Z/W  43.437 CC GG TTNGTATGGATACAACCCATAANNTCTCAAATGGAA 8383077 QTL 11 GAAGCAACAAAAAAACAAGAAAAA[C/G]TGGAGTA CAAACTTATCCGCAAGGTGTTCGATGAAAGTCCTCA AAGAAGTATTATTATAA (SEQ ID NO: 37) NU0218656 Z/W 11  44.62608 AA GG ATGGCTTTTGCAGTGGACCTCTTTACnAAATTCTTCA QTL 11 CCCGATAAACCAGAGATAGTGTT[A/G]AAGGTGAAG TCTTAAATTGTCTGGGCTTGTACAAGAAGTTCACTGA CAAGCTCTTAGTTC (SEQ ID NO: 4) NU0218779 Z/W 11  44.62608 TT GG CCAGCACAACATTGAATGnAAAACCCGATGCCTTTA QTL 11 CATGTCTTTTAATGTCAATTTTCA[T/G]ACTTCCAATG TCCAAACAGAAAAGGAAAAAACCAAAGAGGTCAAA AGTAGGTTTATTCAA (SEQ ID NO: 5) NCMEL00 Z/W 11  45.79 TT AA TTGAAATCTTATGGTTTGAGAATTGCCATGTCACTAT 8383075 QTL 11 CCTTTTAGTTTGTGTAATTTTCAWGTTGCTACTTATT TGGCTCTGGTCATAGAGATCTGTAATGGTTTATTTTT AAGGGGGTAA (SEQ ID NO: 38) NCMEL00 Z/W 11  46.62 CC AA TGAAGGCCATTGATAATTCACTAAAGGTACTATAAG 8383078 QTL 11 AGCCGTGCCTGCTAACCTGCATTC[A/C]GTTATTTTTG GTCAAAGAAAGCAATAAACAACAAAGCAAATAAAT CAAATGGGAANAAAC (SEQ ID NO: 39) NU0220333 Z/W 11  47.94879 GG AA AATTCGTAGAGAGCGTCCTGAACTCCTAGAGAGCGT QTL 11 AAGAGGGTGAGCTACTAACTCATT[A/G]TAGGTTGTT GGTTGAGATCCATGTTAATTGGGAGAACATGGGCAT TTGCCATCAGACTAG (SEQ ID NO: 6) NU0219293 Z/W 11  47.94879 TT GG CTTGTGAAGCTCATACGAGAGAACAAGATGATGAGT QTL 11 CATACAAAGCCGATGTGGCTTCAT[T/G]GGATGATTT GGACCAAAGTAAACACTTCCCACGTCCCCTGCAAAA CCATATTTTATGCAA (SEQ ID NO: 7) NU0218835 Z/W 11  49.00994 CC TT TCCTAGCCCTTTATCAAGGTTATGTCTCCTATTTACC QTL 11 TTTAGACCGACCCATGACGGTTA[T/C]CTAGATATGT CTAGTAGCATTGCACTCTCGGAAGTCCAAACGTCAA CATTGACCTGCCTG (SEQ ID NO: 8) NU0244142 Z/W 11  51.01782 CC AA ATTGAATAAAGCGCACCACCAAGGAAAAGTATCAGT QTL 11 TAGAG[A/C]ATAAAACCAGGAACTAAAATCCTGGAT TTAAATGTCAATGATATGATTTCTTATAGCAAA (SEQ ID NO: 9) NU0219710 Z/W 11  53.43954174 GG AA TTTTAGTGTCAAAACCCAAAGAGATACCGAAAAGTT QTL 11 TATGTGATTGCAAACAGCACCACC[A/G]TTCTCTTTC CAACAGTTGGAAAATCCTCCTATTCCTCTCCCTCAAG TTTCCTAAAAAATT (SEQ ID NO: 10) NU0243767 CMV 12  23.7542249 AA CC GGAACGTTGAAGGTGCATTGGTCAGCCCAAATGGCA QTL 12 TAAACAAAAACTCATAGTGCCCTT[A/C]AGGTGTCCA AAAGGCTGTCTTCTCTACATCATCTGCACACATACGT ATTTGATGGTAACC (SEQ ID NO: 11) NU0220934 CMV 12  29.96041247 TT CC GAAATACCAATGCAAGGATTTGAACACAGAACCTCC QTL 12 TAAACCACACTACTCTATTACCAT[T/C]TAAAATCGC TGATTGGCCCAAAAGCTTAAACTGATAGGTGAAAGC TTATTTAAAATAATA (SEQ ID NO: 12) NU0219654 CMV 12  31.74397834 AA GG TGTATTAGTTAAAGAAATTGTTGAATGATATACTTAC QTL 12 GCTAAGACCACTCTAATGACGAT[A/G]ACCACCACGT TTTCATGGTAGCAAGATTTTATCCCATATTGTAGCTG CAAGTAAAAAGTA (SEQ ID NO: 13) NU0219170 CMV 12  35.48163568 CC GG TGACTTCTGTCCACAGAGCTCGCCACTTCTAATTTAC QTL 12 ATATCTACAAATTTCCAATGCCA[C/G]ATTGATATTG GTGTGACCTTTCTCATTCACTGATCATCAATCTCCAT TTTTCTTGCACTG (SEQ ID NO: 14) NU0243358 CMV 12  39.77151577 GG TT ATACTTTCGACGTAGCTTTATCGTTGTCAGTTCATCA QTL 12 CTCGCCTGTGACGATTTGAATAA[T/G]CACAGGCTTA GCTTAACCTCTCCATTAATTGGGGTTCACTTGGCTGT GACCAAAACTAAG (SEQ ID NO: 15) NU0219184 CMV 12  42.24060998 CC TT ACCATCGATTTGCGTATCATTTACTAGGTGAGTTGTT QTL12 TTCAATGTATTGGAATACCATTT[T/C]ATCTGCACTAT ATAGATTGATAATGAAAATTCTTTGTTTCCTCTCGTC TACCACGTTCAT (SEQ ID NO: 16) NU0219714 CMV 12  43.37621994 AA GG CATAGAAGTCAAGTGATATAAAGAGAGAAACGTAA QTL12 AGCATAGAGGTTTATCCTTACAGTC[A/G]CTTGTTCT CTAAAACATACATTTCCTCCACATCACCTACAAAAC ATTTAACCATATGAGA (SEQ ID NO: 17) NU0218323 CMV 12  44.47221721 AA GG CTACATAAAGCCCTATCGATAGAGGTCTCCAGGTAC QTL12 AATAGTTTCTAGCTAGAGTTAAGG[A/G]AAAGACAA ACATTGTGTAATTGGATAGTTAATGTGGATTAATCCC AGGTTTCATGTTCTA (SEQ ID NO: 18) NU0220980 CMV 12  45.87976958 AA GG CACCACCTTTGACATCACCAAAGGCCGCTTCTCCCTC QTL12 TCCCTACAAATACTATTGGCGAC[A/G]GCTTCTCCTT TTGGTTGACAAAGGTTTATGGCCCTTGCCGATACAA GGATAGGCCTACAT (SEQ ID NO: 19) NU0243527 CMV 12  44.25702765 GG AA ACACAGAGTCGGCGCATCTCTTnGAAACCCTATATG QTL12 ACCGTGAGAAGATGATGGTGCTTT[A/G]ATTCTCTTA CGCAGTACACATTTCCCAAGGCGAGTTAAACTTCAA AATTTAAAAACTATG (SEQ ID NO: 20) NU0220836 CMV 12  46.88602776 AA GG TCTTTCCCAGATTAATGGCTAGGAATTTACTCGGATG QTL12 GTTATTTCTAGAAGTTTTAGTTC[A/G]ATTCTTCCGCA GATTCCCTCCCTTTCAACGGTTGTAACAACTCCCAnA ATTACTCCAAAT (SEQ ID NO: 21) NU0218164 CMV 12  48.4192602 AA GG GTCCTGAGAAGCACAAATACAAATACAAGAAAG[A/ QTL 12 G]AGGATAACCTGATACAAACATGGTAGCATGTCAT ATTTAAAAATCTAGTTATGCTTCAAA (SEQ ID NO:  22) NU0218516 CMV 12  49.58286753 CC AA GAGATAGAGAAAGAAGTAGATAAAGTGATTTCCCG QTL 12 GATTAGAGAAGTAGGGTCAAAAGTA[A/C]GAAGCAA ATTCGACTCCGATGGTACAGTTGTTCAATCTGAGAA CTTGTTGCAnnCGGTGC (SEQ ID NO: 23) NU0218074 CMV 12  51.87481232 TT AA AACAGAAAAGATCAAGAATGAAATGAAAAGGACCT QTL12 TTAAAAGGGAAGCGAAGGCTCTATT[A/T]CTCTTGGA TGTAACTTAAGAAACCTCATAAACATTCAAAGTTTC AAGCTCAACCATAAAA (SEQ ID NO: 24) NU0218603 CMV 12  53.62216566 CC TT CTTATGCTTGAATTAGTAATTTTTGTGTTTTCAGTTCT QTL12 GTGTAGATCCATTTTTTATGCC[T/C]TTCACGTGAAA GCCATTATTAGTGGGTTnAAAATGATGTATCATTTTG CTGCTTCTTAAC (SEQ ID NO: 25) NU0220144 CMV 12  54.5470543 TT CC CATACCGAAAGAAGGCAGTCCAGTCGGCCATGGTCG QTL12 TTTCAGTCTAAGCGGAAACGGTGA[T/C]GGATACATT GGAAATGTTGTCAGTGGTTCAATTTCCCACAAAGAC ACTCTTGGCTGTCGT (SEQ ID NO: 26) CMBR041- zym-1  2   3.2644086 — — GTACCGCCTAGGGTTTCTCC (SEQ ID NO: 27) forward CMBR041- zym-1  2   3.2644086 — — CGAGGAAGAGAGAGAAGGGG (SEQ ID NO: 28) reverse NU0218531 zym-1  2   5.74 AA GG TGTCCAAGGATTTTGTGTTTTCCAGATCAGGAAACC AGTGTACTTCTTCCACATTCGGCT[A/G]TTCCAGCCTT CGATTAGAGCTCGATATTGGATGTAATTANNNANNN NNNNCNNN (SEQ ID NO: 29) NU0220476 CMV  2  80.09862541 TT CC GAATGCTTCCTTTCACATATTTTCTGTGATATTCTTTT QTL 2 CCCTGAACAATGCTGAACCGAA[T/C]ATGGTATCATA TGGATGGATTTATTTATCATATAATTTTCAAAACTTA ATTATATAGCAT (SEQ ID NO: 30) NU0218624 CMV  2  97.51390043 TT GG TCATTGAGTTCAATCGTATGAAGTACTTCTGTGCATG QTL 2 ACTGGCCACTTGAGTCGGTGTTC[T/G]GGATATAACG AAGTTTCTTGAAATGCTTCTCCAATCCCCTTTCCCAA ACTTATCTAGACC (SEQ ID NO: 31) NU0219047 CMV  2 102.664891 GG AA GATCTTTTGAATTACTATTCCTCAACATATCCTTATA QTL 2 ATTTTCATATATCATCACCAAAC[A/G]TTCATCATTTT TCCCTCCATTCTATCAACCAATCCTTCAAACAATCAC AACTCCAAAGAG (SEQ ID NO: 32) NU0220488 CMV  2 107.2270656 CC TT CGTACAGACGGATTGCGCAATGAAGCTATCCCATTT QTL 2 TAACTTCAACAATGAAACGCATCT[T/C]CTCAGCGGC ATTTCATCGAACAATATGGCGAGCGTGCATTGCTAT GCACGGAGAAAnCCC (SEQ ID NO: 33) NU0220264 CMV  2 111.8560636 AA TT CAGTGATATGATAAAATACAAGAATTATGAAGGCTG QTL 2 AAGTTCGAATGAATCTACAATAAT[A/T]GGGTTTTGT TACATAAATCTGAAGTAAAAACTTAnTGAGGCATAC ATTTTTGCATGGAAT (SEQ ID NO: 34) NU0219006 CMV  2 118.453265 TT CC ATCAGGGGTCTGAAGCTGATAATGATGCTGTAAGAA QTL 2 ATAAGATAGAAGAACCTCACAGAA[T/C]GCTTGGTA CTATATCTGGAGAGCATACTACAGTTTCTGATCAGC ACGCGGTTACTAATGA (SEQ ID NO: 35)

Example 2: Identification of Genetic Markers Linked to WMV and ZYMV Resistance Traits

Genetic markers were identified on melon chromosome 11 which are linked to QTL loci conferring resistance to WMV and ZYMV. These two virus resistance traits map closely on chromosome 11. Six F2 segregating populations derived from crosses of PMR45 (a publicly available Western Shipper type melon) and five elite Charentais-type lines to ME8094 were phenotyped for ZYMV and WMV resistance as shown in Table 6 in order to identify and to validate the presence of the “W/z” QTL locus of melon chromosome 11 conferring such resistance. 120 seedlings from each of the six populations were genotyped using markers linked to the W/z locus (resulting in 6-11 polymorphic markers in different F2 populations). In addition, 172 lines of an F5 mapping population derived from a cross of Mbnr992 x GA35PMT were phenotyped for ZYMV (Table 6) and the population was genotyped using 134 TaqMan markers that covered the melon genome.

TABLE 6 F2 and F5 segregating populations phenotyped for ZYMV and/or WMV and their pedigrees. # F2 plants # plants for QTL phenotyped for: mapping analysis: segregating pop. gen pedigree ZYMV WMV ZYMV WMV F2 PMR45 × ME8094 F2 PMR45/ME8094:1. 120 120 117 114 F2 VC1 × ME8094 F2 DX_404.404.3.2/ME8094:8. 120 120 117 111 F2 VC2 × ME8094 F2 DX_225.1J/ME8094:9. 120 120 118 109 F2 VC3 × ME8094 F2 DX_89.95.1.7.1.1.4.M/ME8094:7. 120 120 105 109 F2 VC4 × ME8094 F2 DX_94.94.3.16.2.3.17.10.1/ME8094:7. 120 120 111 114 F2 VC5 × ME8094 F2 DX_1901.A1/ME8094:8. 120 120 111 108 F5 mapping pop F5 C2_Mbnr992/GA35PMT:7.3.1@.0001a. 172 — 163/143* — *163 individuals used for non-parametric interval mapping; 143 individuals used for binary interval mapping.

Analysis was conducted using single-marker regression, non-parametric interval mapping and/or binary interval mapping. Briefly, the F2 segregating population indicated that the most likely location of the W/z locus is in the interval of NU0218779 (or NU0218656) to NU0218835 (44.6 to 49.0 cM on linkage group 11 as shown in Table 4). Only one of the six mapping populations (VC5 x ME8094) indicated association of WMV with markers upstream of this interval (NU0219106 at 39.0 cM); however, this population showed significant distortion of the expected phenotypic segregation ratios at both the F1 and F2 generations and was therefore not considered accurate. This led to a further reduction of the identified genetic interval comprising W/z, as previously the locus was mapped in the interval of 38.97 to 53.44 cM and additional breeding studies further refined the interval to 40.92 to 51.02 cM.

WMV and ZYMV resistance was mapped from the source Mbnr992 (Table 1). Mbnr992 was developed by self-pollinating ME8094. Mbnr992 carries resistances to CMV, WMV, and ZYMV. Inheritance of the ZYMV resistance from Mbnr992 is recessive. Inheritance of WMV resistance from Mbnr992 is mainly dominant, although heterozygotes can show intermediate resistance depending upon weather conditions and virus pressure.

When using Mbnr992 as the resistance donor for breeding, segregating populations demonstrated a very high correlation of resistance to both WMV and ZYMV, suggesting tight linkage of loci (or a single locus) controlling resistance to these two viruses. An F6 RIL population from Mbnr992 x GA35Pmt was phenotyped for virus resistance and genotyped for markers along the melon chromosome. The parent line GA35Pmt is susceptible to WMV, ZYMV, and CMV. From this data the ZYMV resistance locus was mapped to chromosome 11, at approximately 44 to 53 cM, and a close linkage, or co-segregation of a locus controlling resistance to WMV was observed. To verify that WMV is located in this same region as ZYMV two studies were conducted. In the first experiment a selected set of individuals that were recombinant in the ZYMV region were selected from 67 lines of the RIL population Mbnr992/GA35PMT, and a WMV screen was performed. Individual plant scores were taken and Least Square Means (LSM) for WMV score based on plot averages were used to do the QTL analysis. The QTL analysis showed that the major QTL peak was on linkage group 11 in the same region in which ZYMV had previously been mapped, demonstrating that the locus for WMV resistance is co-locating with the ZYMV resistance locus.

A second experiment was then conducted to identify the location of the WMV locus. In this study a BC4F2 population was screened for WMV resistance, and ZYMV resistance was scored on the plants that survived the WMV screen. The plants were genotyped with all the polymorphic markers in the putative WMV/ZYMV region. There were a total of 276 plants, 191 of which were available to also collect the ZYMV resistance data. Markers NU021906 (p<0.01), NU0218656 (p<0.01), NU0219710 (p<0.01), and NU0219542 (p<0.05) were significantly correlated with the WMV resistance trait, while marker NU0218656 correlated with the ZYMV resistance trait (p<0.01). Two markers required follow-up analysis and were subsequently dropped from further analysis. These were NU0218779 and NU0218514. The analysis showed that the WMV resistance trait derived from Mbnr992 source (i.e. ME8094) is located in the same region as the ZYMV resistance trait. Marker NU0218656 demonstrated the tightest linkage to the WMV resistance trait, followed by NU0219710. The strongest significance for ZYMV resistance was found for the marker NU0218656. Thus the two traits co-located.

ZYMV resistance was also mapped from the source PI414723 which carries the zym-1 gene. A F6 RIL population from Vedrantais x PI414723 was phenotyped and genotyped for ZYMV resistance. The parent line Vedrantais is a Charentais type, inbred line susceptible to ZYMV. From this data, a single locus (putatively zym-1) was identified on chromosome 2, position 3.2-5.7 cM. Markers for this locus were converted to a high throughput genotyping format, validated in germplasm from breeding programs, and may also be utilized for marker assisted selection for zym-1. Inheritance of the zym-1 resistance for ZYMV is recessive.

The location of the WMV/ZYMV resistance from Mbnr992 and the zym-1 gene from PI414723 on chromosomes 11 and 2, respectively, demonstrates the independent inheritance of these two ZYMV resistance genes. The WMV/ZYMV resistance locus on chromosome 11 is particularly valuable as it provides dual resistance to two viruses, strong resistance to WMV, no or very low virus titer after mechanical viral inoculation (which has until now been unavailable in melon), and a source for resistance to ZYMV which is not associated with the foliar necrosis typical of the previously identified zym-1 gene. FIGS. 2-4 illustrate disease scores and ELISA test results further demonstrating the efficacy of the ZYMV/WMV resistance trait identified in ME8094.

An F5 mapping population from the cross Mbnr992 x GA35PMT indicated that marker NU0218779 at 44.6 cM is most tightly linked to the ZYMV and WMV resistance trait, with an additive effect of a=3.83, according to the single marker regression analysis. Non-parametric and binary interval mapping analyses indicated that the QTL peak is located at 46.8 and 45.7 cM, and the 1-LOD interval is 43.25-48.75 and 44.25-48.25, respectively. These intervals are in agreement with the results reported above for five of the F2 segregating populations. Markers in the genetic map interval bounded by NU0219106 and NU0219710 (on linkage group 11 as shown in Table 4) may be utilized, among others, in MAS to identify plants carrying resistance to WMV and ZYMV. Other markers localized to this interval on the melon genetic map may similarly be utilized, such as markers publicly available (e.g. see S. E. Martín, “Caracterizatión Etnobotónica Agro-Morfológica, Sensorial, Físico-Química, Nutricional y Molecular de Las Variedades Locales de Melón de Villaconejos;” Ph.D. Thesis, Universidad Politecnica Madrid, 2010).

Example 3: Breaking Linkage of CMV QTL12 to the Pentamerous Fruit Trait

The genomic interval of CMV QTL12 flanked by the markers NU0243358-NU0220836 (39.77-46.89 cM as listed in Table 4) confers CMV resistance, however the pentamerous fruit phenotype maps to a similar location in the C. melo genome, and this undesirable trait is found, for instance, in melon lines comprising an introgression from certain melon lines such as PI161375 and lines derived therefrom. The genetic factor that leads to the pentamerous fruit phenotype in melon has been previously characterized and mapped on LG XII of the ICuGI melon composite map (Périn et al. TAG 104:1017-1034, 2002). Linkage drag resulting in the presence of the undesirable pentamerous fruit trait has however not been observed following introgression of the chromosomal interval from ME8094 for CMV resistance. Thus, use of the CMV resistance trait(s) derived from ME8094 in conjunction with marker assisted breeding allows introgression CMV resistance while avoiding inclusion of the pentamerous trait.

Example 4: Phenotype of ME8094 Donor Line Vs. BC2 Derived Lines Carrying Introgression of Interest

Four to six plants of five pedigrees (Table 7) were planted in a greenhouse nursery. The BC2-derived lines described were derived from the cross of the elite WSH-39-1083-AN to the donor parent EXC-C210-ME-8094-1. At the BC1 generation one random line was selected that carried the donor introgression in the genomic region of interest as shown in Table 7. This line was advanced to BC2 generation and was selfed for at least one subsequent generation to allow fixing the donor introgression. Molecular markers were only used to select the donor introgression at the three indicated genomic regions; therefore, it is not known what other regions of the genome may carry donor introgressions.

Plants of the five pedigrees were arranged in order (not randomized) in two neighboring rows of the greenhouse, far from cooling pads so that temperature differences during growth were not an issue. Data were collected at harvest maturity from 2 fruits for each of the plants. Phenotypes recorded were: fruit length and width, cavity length and width, firmness, Brix (soluble solids), and rind and flesh color. Color data were recorded with a handheld colorimeter and final color phenotypes presented are lightness, chroma and hue. Four independent color measurements were collected from the rind and another four from the flesh of each melon fruit (location on the rind and flesh was consistent for all fruits). Also, two measurements of firmness and Brix were recorded for each fruit using a digital handheld penetrometer and refractometer, respectively. Representative fruit from this study are shown in FIG. 6.

TABLE 7 Summary of ME8094 and BC2 lines derived therefrom, carrying indicated introgressions at loci of interest (CMV QTL12, CMV QTL02 or WMV/ZYMV QTL11). LG/size of Pedigree ME8094 introgression introgression (cM) EXC-C210-ME-8094-1 n/a n/a C2_WSH-39-1083-AN*3/ CMV QTL02 LG2/80.1-118.5 cM EXC-C210-ME-8094- 1:0027.0018.0006. C2_WSH-39-1083-AN*3/ CMV QTL12 LG12/29.6-65.4 cM EXC-C210-ME-8094- 1:0080.0088.0005. C2_WSH-39-1083-AN*3/ ZYMV/WMV QTL11 LG11/44.6-51.0 cM EXC-C210-ME-8094- 1:0063.0007.0010.0147. C2_WSH-39-1083-AN*3/ ZYMV/WMV QTL11 LG11/38.9-56.6 cM EXC-C210-ME-8094- 1:0018.0013.0002.0145.

Table 8 provides phenotypic data for fruit of each pedigree. Mean and standard deviation is also shown for each genotype and trait. These data confirm that the ME8094 donor has more elongated fruit than the BC2-derived lines that carry donor introgressions. The length of the fruit of the ME8094 line was on average 221.07 mm, while that of the BC2 lines ranged from 122.08 to 174.14 mm. Similarly, the size of the cavity was larger in the ME8094 line. Melon fruits of the ME8094 line had also higher firmness (8.62 kgf) than 3 of the 4 BC2-derived lines (4.76 to 5.75 kgf). Soluble solids content (Brix) was very low for fruit of the ME8094 line (3.96° Brix) compared to fruits of the BC2-derived lines (7.94 to 9.55° Brix). FIG. 6 shows the different fruit shape and color of the ME8094 line compared to BC2-derived elite lines carrying donor introgressions at parts of the genome.

TABLE 8 Phenotypic values on a per plant basis for each of the 4 to 6 plants phenotyped for each pedigree. Pot number Pedigree Width Length CavW C212WGH2013-3497 EXC-C210-ME-8094-1 107.92 274.67 53.685 C212WGH2013-3498 EXC-C210-ME-8094-1 114.04 179.07 68.48 C212WGH2013-3499 EXC-C210-ME-8094-1 104.03 251.33 59.14 C212WGH2013-3500 EXC-C210-ME-8094-1 105.44 166.17 55.82 C212WGH2013-3501 EXC-C210-ME-8094-1 100.64 199.77 53.9 C212WGH2013-3502 EXC-C210-ME-8094-1 80.92 255.40 36.455 Mean 102.16 221.07 54.58 St Dev 11.33 45.16 10.44 C212WGH2014-0001 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0027.0018.0006. 100.06 149.33 54.495 C212WGH2014-0002 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0027.0018.0006. 90.91 217.16 46.61 C212WGH2014-0003 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0027.0018.0006. 98.23 179.58 42.89 C212WGH2014-0004 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0027.0018.0006. 111.64 150.51 54.36 Mean 100.21 174.14 49.59 St Dev 8.58 31.91 5.79 C212WGH2015-0001 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0080.0088.0005. 96.96 154.42 40.605 C212WGH2015-0002 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0080.0088.0005. 81.62 146.84 33.105 C212WGH2015-0003 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0080.0088.0005. 97.14 141.80 46.015 C212WGH2015-0004 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0080.0088.0005. 94.06 143.84 44.095 C212WGH2015-0005 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0080.0088.0005. 88.62 140.08 40.64 C212WGH2015-0006 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0080.0088.0005. 95.60 149.74 48.34 Mean 92.33 146.12 42.13 St Dev 6.11 5.35 5.36 C212WGH2016-0001 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0063.0007.0010.0147. 109.42 135.20 57.335 C212WGH2016-0002 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0063.0007.0010.0147. 117.65 176.04 62.135 C212WGH2016-0003 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0063.0007.0010.0147. 114.19 153.19 59.125 C212WGH2016-0004 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0063.0007.0010.0147. 131.81 158.47 75.51 C212WGH2016-0005 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0063.0007.0010.0147. 98.92 121.32 51.98 Mean 114.39 148.84 61.22 St Dev 12.02 21.18 8.80 C212WGH2017-0001 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0018.0013.0002.0145. 104.50 117.97 32.44 C212WGH2017-0002 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0018.0013.0002.0145. 130.94 148.47 54.835 C212WGH2017-0003 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0018.0013.0002.0145. 111.63 111.78 51.35 C212WGH2017-0004 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0018.0013.0002.0145. 127.52 114.95 48.87 C212WGH2017-0005 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0018.0013.0002.0145. 118.93 122.00 59.84 C212WGH2017-0006 C2_WSH-39-1083-AN*3/EXC-C210-ME-8094-1:0018.0013.0002.0145. 116.18 117.33 56.39 Mean 118.28 122.08 50.62 St Dev 9.84 13.36 9.70 Rind Flesh Pot number CavL Firm Brix Lightness Chroma Hue Lightness Chroma Hue C212WGH2013-3497 217.63 10.54 3.68 77.45 13.18 106.90 63.45 20.25 110.05 C212WGH2013-3498 127.89 7.83 4.05 77.38 13.27 102.98 63.28 17.22 104.23 C212WGH2013-3499 197.90 6.22 4.33 77.94 14.10 104.28 63.43 17.41 104.14 C212WGH2013-3500 122.89 8.21 3.78 77.19 13.30 105.57 60.53 21.93 108.40 C212WGH2013-3501 148.46 10.02 3.85 77.09 12.13 108.80 63.84 18.66 110.03 C212WGH2013-3502 210.32 8.92 4.08 77.44 16.29 109.59 68.16 24.03 111.16 Mean 170.85 8.62 3.96 77.41 13.71 106.36 63.78 19.92 108.00 St Dev 42.72 1.57 0.24 0.30 1.41 2.57 2.46 2.69 3.09 C212WGH2014-0001 99.14 7.46 10.15 60.79 9.96 93.93 57.97 35.44 75.36 C212WGH2014-0002 171.34 8.96 6.60 55.23 10.88 99.65 59.87 31.34 87.34 C212WGH2014-0003 129.14 9.60 5.75 51.82 7.65 106.79 63.47 31.00 81.52 C212WGH2014-0004 49.20 7.84 10.55 60.64 13.26 89.19 57.67 37.17 73.83 Mean 112.20 8.46 8.26 57.12 10.44 97.39 59.75 33.74 79.51 St Dev 51.39 0.99 2.44 4.38 2.32 7.58 2.67 3.05 6.18 C212WGH2015-0001 109.67 6.75 9.73 61.61 22.44 96.51 54.69 43.01 69.06 C212WGH2015-0002 102.03 5.33 8.15 61.54 21.09 95.59 57.12 43.37 70.30 C212WGH2015-0003 96.82 6.02 10.38 56.60 11.91 100.23 55.50 43.93 68.52 C212WGH2015-0004 108.66 5.54 8.78 61.19 19.71 90.07 55.10 38.68 71.64 C212WGH2015-0005 97.74 7.64 9.85 59.28 8.85 95.63 55.61 42.09 70.64 C212WGH2015-0006 107.51 3.23 10.40 65.40 22.22 97.32 57.55 35.63 73.36 Mean 103.74 5.75 9.55 60.94 17.70 95.89 55.93 41.12 70.59 St Dev 5.66 1.50 0.90 2.91 5.84 3.33 1.15 3.27 1.76 C212WGH2016-0001 80.70 4.33 9.33 60.52 11.08 102.53 52.99 31.65 113.39 C212WGH2016-0002 109.11 2.39 6.98 62.51 11.37 103.52 56.16 30.86 94.39 C212WGH2016-0003 89.11 4.89 7.93 58.82 13.76 104.40 56.10 33.56 98.58 C212WGH2016-0004 105.36 6.76 9.40 57.24 13.08 102.99 53.40 31.95 111.82 C212WGH2016-0005 74.91 5.44 6.08 58.36 14.32 109.11 59.23 31.00 105.20 Mean 91.84 4.76 7.94 59.49 12.72 104.51 55.58 31.81 104.68 St Dev 14.99 1.61 1.45 2.06 1.44 2.67 2.52 1.08 8.22 C212WGH2017-0001 71.63 5.64 7.40 62.71 8.02 91.09 53.69 40.85 69.16 C212WGH2017-0002 97.88 5.32 7.68 59.67 6.94 94.76 57.37 37.58 73.82 C212WGH2017-0003 78.39 5.36 9.05 60.23 7.04 93.77 54.96 39.03 74.03 C212WGH2017-0004 78.94 5.22 9.40 60.55 7.10 95.77 57.42 40.70 72.73 C212WGH2017-0005 81.29 6.13 8.43 61.49 7.92 93.16 51.12 34.88 76.14 C212WGH2017-0006 70.34 6.13 6.65 62.75 8.76 93.96 54.13 39.80 71.32 Mean 79.74 5.63 8.10 61.23 7.63 93.75 54.78 38.81 72.87 St Dev 9.88 0.41 1.05 1.30 0.72 1.59 2.39 2.27 2.41

Example 5: Validation of QTL2 Markers in Lines with QTL12 Fixed for the ME8094 Introgression

A study was conducted to validate the presence of the CMV genetic factor which was identified in the genomic region of 95.88-118.45 cM on linkage group 2 (LG2) in line ME8094. A total of 16 BC2-derived lines from the cross of WSH-39-1083-AN to ME8094 were tested. Eight entries carried the ME8094 introgression at the CMV QTL12 interval only (QTL2−/QTL12+) and 8 entries carried both CMV QTL2 and QTL12 (QTL2+/QTL12+). Twelve seedlings per replication and 12 replications of each of the 16 entries, as well as the disease control lines Virgos, Paco, Pastis-2, MR1, TopMark, Vedrantais, and the parental lines ME8094 and WSH-39-1083-AN were tested in a complete randomized block design.

Due to the large number of plants, replications 1-6 were sown and inoculated at different timepoints than replications 7-12. Disease scores (in a scale of 1 to 9, 1: resistant, 9: susceptible) were collected for all replications at 9, 15 and 22 days after inoculation. Analysis was conducted using JMP v9 (JMP Software; SAS Institute, Cary, N.C., U.S.A.); and least square means were derived using the restricted maximum likelihood for replications 1-6 and 7-12 separately, as well as across all replications (Table 9). Mean separation groupings indicate entries with significantly different disease scores. Significant differences were observed between the two timepoints possibly due to differences in inoculation since replications 7-12 were more uniformly and severely attacked by CMV, but means of all entries were ranked similarly across all replications.

These results show that all lines carrying both CMV QTL2 and QTL12 (QTL2+/QTL12+) had significantly higher resistance to CMV at 22 days post-inoculation when compared to lines carrying the ME8094 introgression at the CMV QTL12 interval only (QTL2−/QTL12+), with the exception of entry 12. For entry 12 it is possible that other minor loci controlling CMV resistance may be segregating in the background, leading to a higher level of resistance. Entry 13 also displayed higher levels of resistance than typically observed, and in comparison to other QTL2+/QTL12+ entries in this study, which may also be due to other minor loci controlling CMV resistance derived from ME8094 that may be present in this particular BC2-family.

Thus, when QTL12 is fixed for the ME8094 donor introgression, it is possible to identify statistically significant differences among lines carrying and lines lacking the QTL2 ME8094 introgression.

TABLE 9 Least square means and mean separation groupings for disease scores 22 days post-inoculation for all entries and controls. JMP I-all data-22dpi_REML JMP II-rep1-6_22dpi_REML JMP III-rep7-12_22dpi_REML Pedigree Entry LSM Std Error MSG LSM Std Error MSG LSM Std Error MSG ME-8094 17 1.040972 0.162696 K 0.999098 0.215223 J 0.95292 0.23118 K Virgos 18 1.022317 0.222088 K 0.997786 0.293344 J 0.986339 0.31602 K QTL2+/QTL12+ 13 1.111346 0.11296 K 0.999922 0.159501 J 1.224711 0.148963 K Paco 20 2.152872 0.17591 J 1.882778 0.230493 I 2.433454 0.252803 J Pastis-2 21 3.823247 0.18215 H 3.768528 0.263583 G 3.902406 0.234721 I QTL2+/QTL12+ 15 2.930645 0.11626 I 2.18832 0.161796 I 3.699479 0.155587 I QTL2+/QTL12+ 14 2.877832 0.112961 I 2.222418 0.15839 I 3.536354 0.150007 I QTL2+/QTL12+ 4 3.112621 0.11296 I 2.831237 0.159502 H 3.391398 0.148963 I QTL2+/QTL12+ 12 4.154572 0.112567 GH 3.69464 0.15839 G 4.61362 0.148963 H QTL2+/QTL12+ 16 4.303952 0.115837 G 2.97138 0.161799 H 5.649089 0.154436 G QTL2+/QTL12+ 3 7.173897 0.135083 F 6.827129 0.198179 F 7.476804 0.172011 EF QTL2+/QTL12+ 1 6.964789 0.115833 F 6.790369 0.164203 F 7.150718 0.152175 F QTL2+/QTL12+ 2 7.220696 0.12542 F 7.000267 0.181223 F 7.420786 0.161844 EF QTL2+/QTL12+ 9 7.763623 0.119396 E 7.755379 0.172115 DE 7.77718 0.15442 DE QTL2+/QTL12+ 11 7.880127 0.115831 DE 7.757772 0.165433 DE 7.999737 0.151074 CD QTL2+/QTL12+ 8 8.068536 0.114989 DE 7.71644 0.164193 DE 8.410504 0.150008 BC QTL2+/QTL12+ 10 7.757902 0.119877 E 7.542371 0.174971 E 7.976902 0.153291 D QTL2+/QTL12+ 7 8.445322 0.116262 BC 8.453916 0.165441 BC 8.454128 0.152172 B QTL2+/QTL12+ 6 8.710128 0.112567 AB 8.527974 0.15839 BC 8.891398 0.148963 A QTL2+/QTL12+ 5 8.139645 0.113357 CD 8.085799 0.160636 CD 8.196954 0.148963 BCD MR1 19 8.718684 0.131826 AB 8.499747 0.186377 ABC 8.914223 0.173647 A WSH-39-1083-AN 24 8.987906 0.112567 A 8.973418 0.15839 A 9.002509 0.148963 A Top Mark 22 8.920173 0.141613 A 8.859122 0.204988 AB 9.002509 0.182441 A Vedrantais 23 8.94632 0.161482 A 8.935303 0.241386 AB 9.011631 0.202427 A

Example 6: Further Mapping of ZYMV/WMV QTL on Linkage Group 11

As shown in Example 2, the genetic map interval bounded by NU0219106 and NU0219710 on linkage group 11 of the melon genetic map (39.0-53.4 cM) carries alleles for resistance to WMV and ZYMV as in lines ME8094 and Mbnr992. Also, it was found that the marker NU0218779 at 44.6 cM is most tightly linked to the ZYMV and WMV resistance traits. This example provides further genetic mapping and phenotypic information associated with introgression of the ZYMV/WMV QTL of linkage group 11, and flanking donor-derived portions of linkage group 11.

Evaluation of lines that were developed through marker-assisted backcrossing demonstrated significant differences for various phenotypic traits due to linkage drag and background effects when Galia (GAL) and Amarillo (AMA) melons with large introgression at the ZYMV/WMV QTL11 region were tested.

Two of the inbred lines converted with the ZYMV/WMV QTL11 region are GAL-188-DUFFS-AN and AMA-188-DECO-AN. BC3 and BC4 seed of the GAL and AMA converted inbreds, respectively, were obtained, fixed for the ZYMV/WMV QTL11 introgression for the homozygous donor and recurrent parent alleles, and trialed next to the unconverted inbred lines. The two trials were arranged in RCBD designs with 10 replications. A number of traits were evaluated (e.g. fruit size, cavity size, fruit set, brix, firmness, vigor, powdery mildew resistance, netting, sutures, blossom end scar size, rind and flesh color), and data were collected when phenotypic variation was observed among experiment entries.

Two different BC3 families were tested in the GAL trial (6 entries total), which were both derived from the same BC2, while one BC4 family was tested in the AMA trial (3 entries). Genome-wide fingerprinting showed that the percent of recurrent parent for the AMA pedigree was 94.95% and that the AMA converted BC4 line had a donor introgression at QTL11 spanning the region of 8.37-49.01 cM (40.63 cM). The percent of recurrent parent for the second GAL pedigree was 93.94% and the GAL converted BC3 line had a donor introgression at QTL11 spanning the region of 40.62-94.71 cM (54.09 cM). The donor introgressions were initially selected using two informative markers in the QTL11 interval at 38.89 and 44.63 cM, therefore spanning a 5.66 cM genomic region.

Results of the GAL trial are shown on Table 10 and FIG. 7. Significant differences among lines carrying the donor alleles and lines carrying the recurrent parent allele at QTL11 were identified for both BC3 families for fruit length, cavity length, fruit set and maturity and for one BC3 family for brix and cavity width implying that introgression of the donor allele at QTL11 may result in fruit with larger length, later maturity, lower fruit set and lower brix. For four of these eight comparisons there were no significant differences among the phenotypes of the unconverted lines and the line carrying the recurrent parent allele at QTL11, while for the other comparisons these lines differed significantly. In addition, three comparisons among lines of the second BC3 family showed no significant difference among the converted lines but significant differences versus the unconverted inbred control for brix, fruit width and cavity width, implying that the remnant donor introgressions in the background of the converted lines (˜5-6% of genome as discussed above) may be responsible for differences in fruit width and brix.

TABLE 10 Trial of the GAL-188-DUFFE-AN MABC conversion carrying the ZYMV/WMV QTL11 introgression (homozygous donor (DN) and recurrent parent (RP) alleles next to the unconverted inbred lines (FS). Two different BC3 families were evaluated for listed phenotypic traits. Least square means and least square differences are shown. Brix Firmness Fruit Width Fruit Length Cavity Width Cavity Length Fruit set Maturity (° Brix) (kgf) (mm) (mm) (mm) (mm) (# fruit/plot) (DAT) Family Entry LSD LSM LSD LSM LSD LSM LSD LSM LSD LSM LSD LSM LSD LSM LSD LSM 1 FS A 13.3 AB 9.4 BC 124.0 C 124.6 CD 43.6 C 79.0 A 46.4 C 64.4 1 DN D 8.2 B 7.4 BCD 123.1 B 132.5 A 51.0 B 85.4 B 32.6 A 68.8 1 RP C 10.7 AB 9.4 D 117.2 C 121.2 BC 45.3 C 75.7 A 50.6 B 66.4 2 FS B 12.2 A 9.8 CD 120.8 C 122.5 D 40.0 C 78.4 A 47.2 C 64.4 2 DN C 10.0 AB 9.5 A 132.1 A 145.0 A 53.3 A 91.5 B 28.6 A 70.0 2 RP C 10.9 A 10.0 AB 128.5 B 130.7 AB 49.0 BC 80.7 A 42.4 BC 66.0

Results of the AMA trial are shown on Table 11 and FIG. 8. Significant differences likely due to the background of converted lines were found for days after transplant, cavity length and possibly fruit width, cavity width and brix. For fruit set, fruit length and vigor, significant differences were probably due to the donor introgression at QTL11 although background differences were also clear for fruit set and fruit length. The QTL11 introgression resulted in significantly higher fruit set, lower fruit length and lower vigor. The lines carrying the donor introgression at QTL11 also appeared more susceptible to powdery mildew than lines with the RP introgression or unconverted lines, although the statistical significance of this observation was not tested.

TABLE 11 Trial of the AMA-188-DECO-AN MABC conversion carrying the ZYMV/WMV QTL11 introgression (homozygous donor (DN) and recurrent parent (RP) alleles next to the unconverted inbred lines (FS). One BC4 family was evaluated for listed phenotypic traits. Least square means and least square differences are shown. DAT Fruit Set Vigor Firmness Brix Fruit Width Fruit Length Cavity Width Cavity Length (days) (#fruit/plot) (0-1 ratings) (kgf) (° Brix) (mm) (mm) (mm) (mm) Entry LSD LSM LSD LSM LSD LSM LSD LSM LSD LSM LSD LSM LSD LSM LSD LSM LSD LSM FS A 72.8 C 12.3 A 1 A 6.1 A 12.6 B 139.6 A 251.5 B 67.8 A 181.9 DN B 71.0 A 21.3 B 0.1 A 6.2 B 9.8 B 135.9 C 220.5 B 67.4 B 159.8 RP B 71.2 B 14.6 A 0.9 A 5.9 C 9.2 A 152.1 B 231.9 A 71.4 B 161.4

In summary, statistically significant differences were identified among tested lines suggesting that the QTL11 and/or flanking regions around this locus may lead to undesirable phenotypes in the GAL and AMA lines. However, since these differences correspond to different traits in the two trials (GAL: larger fruit length, later maturity, lower fruit set and lower brix; AMA: higher fruit set, lower fruit length and lower vigor) it was concluded that either these effects are dependent on melon type (although unlikely), or are due to genetic factors not very tightly linked to the ZYMV/WMV locus at QTL11. Genetic fingerprinting data showed that the donor introgressions in studied lines covered genomic regions of 54.09 cM and 40.63 cM in the GAL and AMA pedigrees respectively.

Concurrently with these evaluations, lines were developed which carry short introgressions of ZYMV/WMV QTL11, to identify optimal breeding events not leading to undesirable phenotypes. Isogenic lines were tested that carried fixed introgressions of the donor and recurrent parent alleles at the ZYMV/WMV QTL11 region from BC2-derived pedigrees of the cross WSH-39-1083-AN x ME8094 (FIG. 9). Each family comprises an introgressed region of part of the most likely QTL11 genomic region. The trial was arranged in a split plot design with 10 replications. Five fruit collected from the 10-plant plots were phenotyped for a number of relevant traits which displayed phenotypic variation among experimental entries. For this locus, data were collected for fruit size, fruit set, brix, firmness and maturity. Least square means were estimated using the appropriate mixed model in JMP and least square differences were derived using Student's t method.

Results demonstrate that significant differences were identified only for fruit length and width (Table 12) but in different families the donor allele was shown to confer increase or decrease in fruit size, and also a concomitant increase or decrease in brix. Variation is fruit size is not unexpected in BC2 lines that likely still carry a significant amount of donor genome (ME8094 has drastically different size from elite melon lines) and heterozygous genomic regions. Overall, differences among the isogenic lines for the five families tested were inconsistent and do not reveal any trend even after taking into consideration that different events were tested for each family

TABLE 12 Least square means and least square differences for phenotypic data collected from five BC2-derived families with the ZYMV/WMV QTL11 introgression fixed for the homozygous donor (DN) or the homozygous recurrent parent (RP) alleles. Firmness Brix Fruit Width Fruit Length Fruit set DAT BC2F4 (kgf) (° Brix) (mm) (mm) (# fruit/plant) (days) family QTL11 LSM LSD LSM LSD LSM LSD LSM LSD LSM LSD LSM LSD 1 RP 5.3 BC 9.3 D 121.8 AB 116.9 EF 4.2 CD 61.0 CD 1 DN 4.9 C 9.4 D 113.1 C 114.5 F 4.2 CD 60.6 CD 2 RP 4.5 C 7.1 F 121.8 AB 139.4 B 4.5 BC 62.9 A 2 DN 4.5 C 7.6 E 123.1 A 146.2 A 4.0 CD 62.9 A 3 RP 6.9 A 12.0 A 124.9 A 122.6 DE 3.0 F 62.6 AB 3 DN 6.8 A 11.8 A 117.2 BC 124.7 CD 3.4 EF 61.4 BC 4 RP 6.2 AB 11.0 B 100.8 E 112.5 F 5.2 A 61.1 CD 4 DN 5.2 BC 10.5 C 95.8 F 113.3 F 5.5 A 60.0 D 5 RP 5.2 BC 11.2 B 107.5 D 112.3 F 4.7 B 61.9 ABC 5 DN 4.7 C 11.2 B 113.2 C 129.5 C 3.8 DE 61.5 BC

These results lead to the conclusion that no undesirable phenotype is associated with these short events developed in the ZYMV/WMV QTL11 genomic region (FIG. 9). Two of these breeding events spanning 3.12 and 5.95 cM, respectively, at the ZYMV/WMV QTL11 locus (FIG. 10) were tested with the appropriate ZYMV and WMV bioassays to confirm efficacy (resistance to the two viruses). Both events were resistant to ZYMV and WMV, which implies that both events can be deployed for marker-assisted selection and backcrossing of this locus, and that the most likely region of this QTL can be narrowed down to the interval of 44.6 to 48.0 cM (between markers NU0218779 and NCMEL008383078).

Example 7: Further Mapping of CMV QTL on Linkage Group 12

As discussed for instance at Example 3, the genetic map interval between NU0243358 and NU0220836 on linkage group 12 of the melon genome (39.8-46.8 cM) controls resistance to CMV. However, lines carrying the ME8094 introgression at this genomic region were found to have irregular shape and enlarged blossom end scars (FIG. 11). Therefore, an effort was initiated to fine-map this genomic region and develop lines carrying shorter introgressions in this region.

To fine-map CMV QTL12, a study was initiated with 28 entries of which 20 were lines with recombination events in the QTL12 region (BC2-derived lines from the cross of WSH-39-1083-AN with the trait donor ME8094) and 8 were resistant and susceptible controls. The experiment was arranged in an RCBD design and had 10 replications. Replications 1-5 were sown on Jul. 5, 2011 and replications 6-10 were sown on Jul. 11, 2011; seedlings were inoculated on 7/13, 7/19 or 7/20 depending on the seed germination. Seedlings were scored for disease 6, 9 and 14 days after inoculation (dpi) and the area under the disease progress curve (AUDPC) was calculated. Replications 1-5 and replications 6-10 were treated as timepoints 1 and 2, respectively, and a mixed model was used to understand whether least square means can be derived across the 10 reps for each entry. Statistical analysis showed that the entry by timepoint interaction was highly significant; therefore, least square means were derived separately for each of the two timepoints (FIG. 12). One entry was removed due to very low germination that resulted in a large number of missing data points. Least square means of entries ranked relatively similar in comparison to controls with the exception of entry 20; therefore, results were consistent between timepoints 1 and 2.

It should be noted that the lines which scored as susceptible (e.g. rows 1-3, 9, 11-16, 21, and Vedrantais in FIG. 12A) had very consistent phenotypes with disease scores of 7 to 9 at 6, 9 and 14 dpi and, therefore, AUDPC of 79-88 for the majority of seedlings across replications. However, all the lines scored as intermediate resistant (e.g. rows 5-8, 10, 17-19 in FIG. 12A) had variable disease scoring resulting in AUDPC of 0-88 and, therefore, higher standard errors. This was primarily due to lower disease scores (resistant or intermediate resistant) during the 6 and 9 dpi and progressively higher scores (susceptible) during the 14 dpi scoring, that have been observed previously and imply the need for evaluation of the CMV material past the seedling stage. Due to the highly variable AUDPC scores that were used for calculation of least square means, least square means for the 14 dpi disease scoring were also derived, which were in agreement (FIG. 12).

Comparison of the 19 lines carrying recombination events for QTL12 leads to the conclusion that the likely region of the genetic factor conferring resistance to CMV on linkage group 12 is located between NU0243358 and NU0218323, spanning the genetic interval of 39.77 to 44.47 cM on the melon genetic map as schematically shown in FIG. 12B.

Next, melon lines comprising shorter introgressions from the resistant parent line in the fine-mapped genomic region of CMV QTL12 were developed for further breeding use, and these lines were evaluated for undesirable phenotypes. BC3-derived families of the cross WSH-39-1083-AN x ME8094 were studied after developing isogenic lines that carried fixed introgressions of the donor and recurrent parent alleles at the CMV QTL12 region (FIG. 13). Each family had undergone a unique recombination event that covered part of the most likely QTL12 genomic region (shown on FIG. 13). The trial was arranged in a split plot design with 10 replications. Five fruit collected from the 10-plant plots were phenotyped for blossom end scar size, fruit length and width since they were previously identified as putative drag due to the CMV QTL12 introgression, but additional traits were visually evaluated and brix data were collected from selected families Least square means were estimated using the appropriate mixed model in JMP and least square differences were derived using Student's t method. Significant differences were not found among isogenic lines for any trait, with only one exception (fruit length of family 6), as shown on Table 13.

TABLE 13 Least square means and least square differences for phenotypic data collected from BC3-derived families with the CMV QTL12 introgression fixed for the homozygous donor (DN) or recurrent parent (RP) alleles. The recurrent parent was also included in two entries of the trial. Phenotypes of blossom end scar size (BES), fruit length and fruit width are all presented in mm. BC3 BES Width Length family QTL12 LSD LSM LSD LSM LSD LSM 1 DN DEF 37.13 G 114.07 G 115.28 1 RP CD 38.96 FG 114.82 G 116.13 2 DN CDE 38.52 EFG 116.03 FG 118.37 2 RP DEF 36.67 EF 117.88 F 120.66 3 DN FG 34.01 E 118.30 E 127.16 3 RP EF 35.32 DE 118.97 E 127.60 4 DN GH 31.56 DE 118.55 A 142.88 4 RP H 29.58 EFG 116.30 AB 140.96 5 DN A 46.46 A 131.37 CD 136.53 5 RP A 45.90 A 132.15 BC 138.52 6 DN BC 40.78 B 126.40 ABC 139.20 6 RP BC 41.04 BC 124.00 D 132.71 WSH-39-1083-AN BC 40.80 BC 123.73 E 125.39 WSH-39-1083-AN AB 43.35 CD 121.62 E 125.10

It is concluded that no undesirable phenotype is associated with these “short” introgressions in the CMV QTL12 genomic region (FIG. 13). Therefore, three selected lines comprising an introgressed region spanning a 3.3-9.1 cM interval (FIG. 14) were tested with the appropriate bioassay to confirm efficacy (resistance to CMV). The events were found to be intermediate resistant, resistant and highly resistant (FIG. 14). This is likely due to the CMV QTL12 having a moderate effect and additional minor QTL conferred by ME8094 are likely present in these BC2-derived lines. Lines comprising the introgressed region, for instance as represented by these three, are efficacious and lack undesirable phenotypes. 

1. A melon plant comprising resistance to Zucchini Yellow Mosaic Virus (ZYMV) and Watermelon Mosaic Virus (WMV), wherein the plant further comprises at least one trait selected from the group consisting of: produces fruit with a width to length ratio of at least 0.5; produces fruit with orange flesh color, green flesh color, or white flesh color; demonstrates fruit Brix≥9.5° Bx; displays resistance to CMV; displays resistance to MNSV; displays resistance to PRSV; and displays resistance to Powdery Mildew.
 2. The melon plant of claim 1, wherein the at least one trait is a width to length ratio of at least 0.5.
 3. The melon plant of claim 1, wherein the at least one trait is selected from the group consisting of orange flesh color, green flesh color, and white flesh color.
 4. The melon plant of claim 1, wherein the at least one trait is Brix≥9.5° Bx.
 5. The melon plant of claim 1, wherein the at least one trait is resistance to CMV.
 6. The melon plant of claim 1, wherein the at least one trait is resistance to Powdery Mildew.
 7. The melon plant of claim 1, wherein the at least one trait is resistance to MNSV.
 8. The melon plant of claim 1, wherein the at least one trait is resistance to PRSV.
 9. A part of the melon plant of claim 1, wherein the plant part is selected from the group consisting of: a seed, a root, a leaf, a stem, pollen, an ovule, an anther, a pistil, and a cell.
 10. A tissue culture of regenerable cells of the plant of claim
 1. 11. The tissue culture of claim 10, comprising cells or protoplasts from a plant part selected from the group consisting of embryo, meristem, cotyledon, pollen, leaf, anther, root, root tip, pistil, flower, and seed.
 12. The plant of claim 1, which is inbred.
 13. The plant of claim 1, which is hybrid. 14-55. (canceled)
 56. The melon plant of claim 1, wherein the plant comprises resistance to Zucchini Yellow Mosaic Virus (ZYMV) and Watermelon Mosaic Virus (WMV) conferred by a locus on Chromosome 11 that comprises a genetic marker selected from the group consisting of NU0219106, NU0218916, NU0219099, NU0218656, NCMEL008383076, NCMEL008383077, NU0218779, NCMEL008383075, NCMEL008383078, NU0220333, NU0219293, NU0218835, NU0244142, and NU0219710.
 57. The melon plant of claim 56, wherein the locus is derived from line ME8094, a representative sample of seed of said line having been deposited under NCIMB accession number
 41653. 58. The melon plant of claim 1, further defined as comprising a locus contributing to CMV resistance on melon linkage group
 12. 59. The melon plant of claim 58, wherein the locus comprises a genetic marker selected from the group consisting of NU0243358, NU0218323, NU0219184, NU0219714, NU0220980, NU0243527, NU0220836, NU0218164, NU0218516, NU0218074, NU0218603, and NU0220144.
 60. The melon plant of claim 1, further defined as comprising a locus contributing to CMV resistance on melon linkage group
 2. 61. The melon plant of claim 60, wherein the locus comprises a genetic marker selected from the group consisting of NU0220476, NU0219006 NU0218624, NU0219047, NU0220488, and NU0220264. 